To explore the effects of long-term different fertilization on soil microbial biomass carbon,nitrogen and enzyme activity of double cropping maize in Southern China.Based on a 35 a long-term located experiment in dryland red soil in Jinxian,Jiangxi Province,four treatments including no fertilizer(CK),chemical fertilizer(NPK),chemical fertilizer and fresh pig manure(NPKM),and fresh pig manure(OM).The soil nutrients,microbial biomass carbon,nitrogen and enzyme activities were measured in the 0—20 cm,20—40 cm soil layers at the maturity of double cropping maize and the correlations between them were analyzed.Results showed that long-term fertilization(NPK,NPKM and OM)significantly increased soil microbial biomass carbon,nitrogen and enzyme activity.During the spring maize period,the soil microbial biomass carbon and nitrogen content of fertilization treatment compared with CK increased by 67.05%—159.15% and 3.33%—62.37% in the 0—40 cm soil layer.And the activities of catalase,phosphomonoesterase,urease and sucrase increased by 0.22%—79.71%,9.82%—59.51%,8.73%—82.37%,66.67%—538.89%,respectively.During the autumn maize period,the soil microbial biomass carbon and nitrogen content of fertilization treatment compared with CK increased by 36.30%—136.72% and 17.09%—47.29% in the 0—40 cm soil layer.And the activities of catalase,phosphomonoesterase,urease and sucrase increased by 7.41%—74.55%,22.69%—57.39%,18.85%—58.98% and 51.70%—216.67%,respectively.Among them,the NPKM treatment had the best improvement effect.In general,soil microbial biomass carbon,nitrogen and enzyme activity in 0—20 cm soil layer were higher than in 20—40 cm soil layer,and the soil microbial biomass carbon,nitrogen and enzyme activity in autumn maize period were higher than those in spring maize period.NPKM and OM treatments also significantly increased soil pH,organic carbon,total nitrogen,total phosphorus,total potassium,available phosphorus,available nitrogen and available potassium.After long-term application of organic fertilizer,soil phosphorus accumulation was obvious,while NPK treatment accelerated soil acidification.All treatments could significantly increase maize yield(P<0.05). Compared with CK, it increased by 1.04—15.07 times. In conclusion,organic-inorganic application(NPKM)is the best fertilization measure to enhance soil nutrients,microbial biomass,enzyme activity and yield.

In order to study the differences in yield,accumulation and utilization of nitrogen (N),phosphorus (P) and potassium (K)among wheat varieties from different geographical origins and among high and low yield wheat varieties from the same geographical origin in dryland farming, 165 varieties from China(58),the International Maize and Wheat Improvement Center(CIMMYT,42)and others abroad (65)were planted in the farm of Henan University of Science and Technology in Luoyang,Henan Province, to analyze the yield and its components,the characteristics of accumulation,distribution and requirement at maturity of N,P,K.Compared with others abroad,the grain yield,grains per spike,1000-grain weight,N,P and K physiological efficiency of CIMMYT varieties were significantly increased by 21.3%,39.1%,26.4%,33.2%,22.6% and 36.1%,respectively,while those of Chinese varieties were increased by 10.5%,18.1%,24.3%,29.4%, 12.1% and 24.3%,respectively,however,the spike number,the N,P and K accumulation in stem and leaf,the N,P,K and dry matter requirements of 100 kg grains of CIMMYT and Chinese varieties decreased significantly,moreover,the increase and decrease of CIMMYT varieties were higher than those of Chinese varieties.Compared the low-yield varieties from the same geographical origin,the yield,spike number,grain number per spike and biomass of Chinese high-yield varieties were significantly increased by 122.4%,38.7%,39.3% and 96.1%,respectively;the yield,spike number and biomass of CIMMYT high-yield varieties were significantly increased by 97.6%,68.2% and 71.7%;the yield,spike number,grain number per spike,1000-grain weight and biomass of high-yield varieties of others abroad were significantly increased by 157.2%,33.0%,43.6%,35.9% and 76.4%.For Chinese varieties,compared with the low-yield varieties, the shoot and grain N,P,K accumulations of high-yield varieties were significantly increased by 98.8%,101.0%,83.7% and 118.8%,104.7%,131.2%,as well as the N,P,K uptake efficiencies were significantly increased by 93.6%,84.6% and 70.3%,the nutrient requirements for grain N,P,K content formation were significantly increased by 102.8%,109.5% and 75.9%,but the K and dry matter requirements for 100 kg grains formation were significantly decreased by 16.8% and 11.1% respectively.For CIMMYT varieties,compared with the low-yield varieties, the N,P,K uptake efficiencies in high-yield varieties were significantly increased by 68.5%,71.4% and 63.6%,as well as the nutrient requirements for grain N,P,K content formation were significantly increased by 79.2%,81.7% and 76.5%,while the N and P requirements for 100 kg grains were significantly decreased by 10.7% and 10.3%,respectively.For others abroad,compared with the low-yield varieties, the N,P, K physiological efficiencies in high-yield varieties were increased significantly by 34.7%,30.2% and 60.6%, as well as the nutrient requirements for grain N,P,K content formation were increased significantly by 73.0%,110.8% and 52.1%,while the N,P,K and dry matter requirements for 100 kg grains were significantly decreased by 26.7%,23.6%,36.8% and 24.7%,respectively.To sum up,many characteristics of grain formation and N,P,K absorption and utilization in wheat showed significant differences among different geographical origin varieties.CIMMYT varieties had higher grain number per spike,1000-grain weight,harvest index,grain N accumulation,and P,K physiological efficiency,while others abroad had higher spike numbers,N,P,K accumulation in stem and leaf,N,K accumulation in shoot and uptake efficiency,dry matter and N,P,K requirements for 100 kg grains,and the values of most indexes of Chinese varieties were between CIMMYT varieties and others abroad.Compared with low-yield varieties,high-yield varieties from the same geographical origin had the ability to improve yield components,harvest index and nutrient uptake efficiency,while increased the nutrient requirements for grain N,P,K content formation.Therefore,the N,P,K input should be increased appropriately in the production system which aimed to high yield and high nutrient content.

In order to clarify the influence mechanism of total replacement of chemical fertilizer with organic fertilizer on the nitrogen fertility of tea garden soil.Based on the 5 a experiment of replacing chemical fertilizer with organic fertilizer in tea garden,single application of chemical fertilizer(CF)and full application of organic fertilizer(OF)were selected as treatments,the effects of total replacement of organic fertilizer with chemical fertilizer on the physical and chemical properties,mechanical stability,aggregate composition,and aggregate inorganic nitrogen distribution characteristics of tea garden soil in rainy and dry seasons were studied,and the influencing factors of aggregate inorganic nitrogen distribution were analyzed.The results showed that:Compared with CF treatment,OF treatment increased the pH value,organic matter content and total nitrogen content of surface soil in rainy and dry seasons.However,there was no significant difference in soil pH between the two treatments in the rainy season(P>0.05);in the rainy season,the cation exchange capacity,ammonium nitrogen content and nitrate nitrogen content in the surface soil of the tea garden under the OF treatment were lower or significantly lower(P<0.05)than those under the CF treatment,while in the dry season,the OF treatment was significantly higher than that under the CF treatment(P<0.05),with an increase of 27.02%, 58.97%, and 266.84%, respectively. Different treatments had significant effects on the mass percentage of 0.25—2.00 mm and<0.25 mm aggregates and GWD;compared with CF treatment, OF treatment increased the mass percentage of 0.25—2.00 mm aggregates and GWD, and decreased the mass percentage of<0.25 mm aggregates; seasons had a significant effect on the mass percentage of aggregates<0.25 mm (P<0.05).The contents of ammonium nitrogen and nitrate nitrogen in aggregates of different treatments were as follows:<0.25 mm aggregates were the highest,0.25—2.00 mm aggregates were the second,and>2.00 mm aggregates were the lowest;in rainy season,the content of ammonium nitrogen and nitrate nitrogen in aggregates at all levels of OF treatment was lower or significantly lower(P<0.05) than that of CF treatment,while in dry season,OF treatment was significantly higher than that of CF treatment(P<0.05);compared with the rainy season,the content of ammonium nitrogen and nitrate nitrogen in aggregates at all levels under CF treatment was significantly reduced in dry season(P<0.05),and the content of ammonium nitrogen and nitrate nitrogen in aggregates at all levels under OF treatment was increased or significantly increased in dry season(P<0.05);under different treatments,the proportion of ammonium nitrogen and nitrate nitrogen storage of aggregates showed that 0.25—2.00 mm aggregates were the highest(51.70% and 51.14%),>2.00 mm aggregates were the second(34.59% and 35.51%),and<0.25 mm aggregates were the lowest(13.71% and 13.34%);compared with CF treatment,OF treatment significantly reduced the proportion of<0.25 mm aggregate ammonium nitrogen storage in rainy and dry season and the proportion of <0.25 mm aggregate nitrate nitrogen storage in dry season(P<0.05),and significantly increased the proportion of 0.25—2.00 mm aggregate ammonium nitrogen storage in rainy season and 0.25—2.00 mm aggregate nitrate nitrogen storage in dry season(P<0.05).Correlation analysis showed that the content of ammonium nitrogen in soil aggregates was mainly affected by soil pH,cation exchange capacity and total nitrogen content,while the content of nitrate nitrogen in soil aggregates in tea garden was mainly affected by soil pH,organic matter content and total nitrogen content;further RDA analysis showed that soil pH and cation exchange capacity were the main factors affecting the distribution of inorganic nitrogen in soil mechanically stable aggregates.To sum up,total replacement of chemical fertilizer with organic fertilizer in tea garden is beneficial to improve the content of soil organic matter,coordinate the supply of soil nitrogen in rainy and dry seasons,and promote the formation of large aggregates and the accumulation of soil inorganic nitrogen.

Based on the long-term improvement experiment of organic fertilizer of soda saline-alkali soil in Songnen Plain,the effects of different improvement years(4,11,15,20 a)on soil colloid components,soil organic carbon components and soil organic-mineral compound degree were studied with no improvement as the control(CK).The results showed that with the increase of improvement years,the colloidal content of soil water dispersive group(G₀)decreased significantly(P<0.05),while that of soil calcium-binding complex(G₁)increased significantly(P<0.05);there were no significant changes in colloid content of soil iron and aluminum oxide binding complex(G₂)and(G₀+G₁+G₂)content of different treatments;the organic carbon content in G₀ group,G₁ group and G₂ group showed an increasing trend.Organic carbon content and heavy fraction organic carbon content of all organic fertilizer treatments were significantly increased compared with CK(P<0.05).In all treatments,organic carbon content in 4 a treatment was the highest,and heavy fraction organic carbon content in 11 a treatment was the highest.The total contribution rate of soil carbon sequestration of the treatments complexes with improved years of 11 a or more was 35.51%—54.64%.Compared with CK,organic-mineral compound degree of soda saline-alkali soil treated with organic fertilizer increased to varying degrees,and the increase was obvious in the treatment of 11 a and above.In conclusion,the long-term application of organic fertilizer promoted the transformation of water dispersive colloid of soda saline-alkali soil to water stable complex,significantly increased the contribution rate of the complex to soil carbon fixation,and significantly improved the degree of organic-mineral composition of the soil.

In order to select a reasonable fertilization pattern suitable for high-yielding and high-quality production of rice stubble weakly glutenous wheat,this experiment was conducted with weakly glutenous wheat Ningmai 13 and Wanximai 0638 as the test varieties,with no fertilization(CK),conventional fertilization of compound fertilizer+urea(T1),slow-release blended fertilizer(T2),loss-control fertilizer(T3),humic acid compound fertilizer(T4),and wheat formula fertilizer(T5),under the same conditions of nutrient supply,the effects on dry matter distribution and transport,filling,yield and quality of weakly glutenous wheat were analyzed.The results showed that slow-release blended fertilizer and wheat formula significantly increased the post-flowering dry matter production,and increased wheat grain filling rate,effective filling days,and grain weight compared with conventional fertilizer application.The grain yield increased by 9.27%—24.30% and 11.64%—22.98% respectively compared with conventional fertilizer.Slow-release blended fertilizer 2 years two varieties than conventional fertilization treatment of nitrogen fertilizer agronomic efficiency increased by an average of 23.14%, 36.88%, wheat formula fertilizer two years two varieties than conventional fertilization increased by an average of 36.31%, 39.35%. Wheat formula fertilizer treatment of two wheat varieties for testing grain quality had reached the national standard of weak gluten wheat. In summary,wheat formula fertilizer can be used as one of the fertilization patterns for high-yielding and high-quality production of rice stubble weak-gluten wheat in the test area,or appropriately reduce the application amount of slow-release blended fertilizer as the fertilization pattern for high-yielding and high-quality production of rice stubble weak-gluten wheat.

In order to explore the effects of irrigation method and topdressing nitrogen on grain yield,quality and nitrogen accumulation and translocation of furrow-seeding wheat in dryland,a field experiment including five treatments,i.e.no irrigation and no topdressing nitrogen(NIND),every furrow irrigation and no topdressing nitrogen(EFIND),alternative furrow irrigation and no topdressing nitrogen(AFIND),every furrow irrigation and topdressing nitrogen(EFITD)and alternative furrow irrigation and topdressing nitrogen(AFITD),were set at jointing stage based on a no-tillage furrow-seeding wheat field from October 2019 to June 2020.The grain yield and its components,main quality index,as well as the shoot nitrogen accumulation,translocation and distribution were measured.The results showed that irrigation at jointing stage,irrigation mode and topdressing nitrogen significantly regulated the yield,quality and nitrogen accumulation and translocation of furrow-seeding wheat in dryland,and the regulation effects was additive.Compared with NIND,the grain yields in EFIND,AFIND,EFITD and AFITD were significantly increased by 46.57%,67.72%,83.71%,95.88%,as well as the nitrogen accumulation at anthesis,the post-anthesis nitrogen accumulation and its contribution rate to grain were significantly increased,so the nitrogen accumulation amounts at maturity were significantly increased by 25.94%,41.00%,65.86%,82.64%.Compared with NIND,the quality in EFIND,AFIND and EFITD was significantly decreased,while that in AFITD did not decrease or even significantly increased.Compared with EFI,AFI did not affect the nitrogen accumulation at anthesis,but significantly increased the post-anthesis nitrogen accumulation,and thus significantly increased the total nitrogen accumulation at maturity and grain nitrogen accumulation.Finally,compared with EFI,the grain yield in AFI was significantly increased,but the difference of quality indexes except the sedimentation value was not significant under ND,while the significant improvement of grain yield and various quality indexes was observed under TD.Compared with ND,the nitrogen accumulation at anthesis,pre-anthesis nitrogen accumulation and its translocation amount,post-anthesis nitrogen accumulation and its contribution rate to grain in TD were significantly increased,and thus the shoot nitrogen accumulation and grain nitrogen distribution rate at maturity were also significantly increased,so the grain yield,grain nitrogen accumulation and grain quality were significantly improved.Moreover,the regulation effect on quality under AFI was greater than that under EFI.In conclusion, AFITD could not only improve the shoot nitrogen accumulation at anthesis and after anthesis, but also significantly increased the amount of pre-anthesis nitrogen translocation to grain, and the shoot nitrogen accumulation and its distribution rate in grain at maturity, thus finally synergistically improved grain yield and quality of furrow-seeding wheat. Therefore, alternative furrow irrigation combined with topdressing nitrogen at jointing stage could be recommended as an alternative mode in dryland.

In order to investigate the effects of nitrogen application rates on the accumulation and distribution characteristics of dry matter and nitrogen,yield and components of maize in the key growth period under different ecological conditions in Inner Mongolia,experiments were carried out in three ecological zones,Tumed Right Banner of Baotou City,Harqin Banner of Songshan District of Chifeng City and Wuyuan County of Bayannur City of Inner Mongolia in 2021.Using maize varieties Xianyu 335,Zhengdan 958 and Jingke 968 as experimental materials,the effects of nitrogen application rate on dry matter and nitrogen accumulation,distribution,transport and yield formation in different organs of maize were studied.The results showed that the interaction between ecological zone and nitrogen fertilizer had a extremely significant effects on dry matter accumulation and distribution,nitrogen accumulation and distribution,yield and its component factors.The proportion of dry matter in various organs of maize varieties in different ecological regions was different,in order of grain>stalk>cob+bract>leaf blade.The difference was mainly manifested in the silking maturity stage. At N2 level,Xianyu 335 had higher dry matter accumulation before flowering and Zhengdan 958 had higher dry matter accumulation after flowering.At the N1 level,the stalk transfer volume,stalk transfer rate and stalk contribution rate of Jingke 968 showed good performance.The nitrogen accumulation of maize varieties with different nitrogen efficiency showed an increasing trend with the advance of growth period.The nitrogen distribution in all organs at maturity stage was grain>leaf blade > cob + bract > stalk.The maize yield in different ecological regions was Harqin Banner>Wuyuan County>Tumed Right Banner.Under the N0 level of Tumed Right Banner,the yield was Xianyu 335>Jingke 968>Zhengdan 958;at the N1 and N2 levels,the yield performance was Zhengdan 958>Jingke 968> Xianyu 335.At the different nitrogen levels in Wuyuan County and Harqin Banner,the yields were Zhengdan 958>Jingke 968>Xianyu 335,and the differences between varieties were significant(P<0.05).In conclusion,the response of nitrogen fertilizer level to Xianyu 335 dry matter accumulation was better in Wuyuan County and Tumed Right Banner.And the response of Jingke 968 and Zhengdan 958 to dry matter accumulation was better in Harqin Banner.Compared with Jingke 968,Xianyu 335 and Zhengdan 958 had better utilization of nitrogen fertilizer at the later growth stage.

To determine the effects of different nitrogen levels on soil nutrient characteristics and on the differences in nitrogen,phosphorus,and potassium uptake and utilization of summer maize,a field experiment had been conducted at four nitrogen rates(N0:No nitrogen application;N1:90 kg/ha;N2:195 kg/ha;N3:300 kg/ha)following nitrogen application of 240 kg/ha on preceding winter wheat.The experimental material Cangyu 76 was used to research the effects of nitrogen application rate on different characters of growth indicators and their correlation.The results showed that the dry matter weight of stem,leaf and corn crobs increased with the increase of nitrogen application ranged in 0-195 kg/ha.Soil nitrate N content in 0-20 cm and 20-40 cm soil layers increased significantly with increasing N application rate;but the content of available P and available K in the same soil layer had no significant change.There were significant differences in nitrogen concentration and nitrogen accumulation in stems,leaves,corn cobs and grains under different nitrogen application rates,in which nitrogen accumulation in seeds accounted for 59.4%-63.5% of total nitrogen accumulation in above-ground parts of plants.The P and K contents in stems,leaves,corn crobs and grains had little change under nitrogen application rate,but was positively regulated by dry matter weight.When N input exceeded 195 kg/ha,nitrogen agronomic efficiency was decreased significantly.When the nitrogen rate was higher than 189 kg/ha,grain yield would be not increased,which was evaluated by Linear plus platform model that simulate the relationship between yield and nitrogen application rate.Therefore,combined with experimental and model simulation results,the optimal nitrogen input was controlled within the range of 189-195 kg/ha,which could realize both economic benefits and agroecological benefits.

To investigate the effects of different application rates of nitrogen fertilizer on soil characteristics of spring wheat and pea intercropping,spring wheat monoculture and pea monoculture.Three planting methods including intercropping of wheat and pea(SI),sole cropping of spring wheat(SS)and sole cropping of pea(PS)were set,and four nitrogen application levels 0(N0),90(N1),180(N2),270 kg/ha(N3)were set.At 85 days after sowing,the activities of five soil enzymes,including sucrase, β-glucosidase,urease,glutaminase and phosphatase,and the contents of five soil nutrients,including total nitrogen,alkali-hydrolyzed nitrogen,total phosphorus,available phosphorus and organic carbon were measured.The results showed soil sucrase activity was increased(65.51%,57.88%)by N application(N2,N3)in PS soil,and N2 level reached the maximum value.Under four nitrogen levels,the sucrase activity of SI planting pattern was significantly increased by 31.25%-94.07% compared with PS.N3 treatment significantly increased SS β-glucosidase activity(17.81%);soil urease activities in SS and SI were increased by N application,and reached the highest at N2 level,SI>SS>PS under the same fertilization;N2 significantly increased the glutaminase activities in SS,SI and PS soils(26.95%,67.05%,55.03%,respectively).Soil phosphatase of SS,SI and PS all reached the highest level in N2,and SI was significantly higher than SS and PS(increased by 128.35%,337.21%,respectively).Nitrogen application could increase soil alkali-hydrolyzed nitrogen,total phosphorus and available phosphorus contents,among which alkali-hydrolyzed nitrogen and available phosphorus reached the highest at N2 level;soil sucrase activity was very significantly correlated with the urease, phosphatase, and significantly correlated with the available phosphorus content. Soil urease activity was very significantly correlated with phosphatase activity and alkaline hydrolyzable nitrogen content, and was significantly correlated with total nitrogen and available phosphorus content. Soil phosphatase activity was very significantly correlated with total nitrogen, available phosphorus content, and significantly correlated with alkaline hydrolyzable nitrogen. The total nitrogen content of soil was very significantly correlated with alkaline hydrolyzable nitrogen.There was a significant interaction between nitrogen treatment and planting mode pattern on soil urease,glutaminase,phosphatase activities,soil total phosphorus,available phosphorus contents.In conclusion,180 kg/ha was the best nitrogen application rate,and intercropping was better than monoculture under the same nitrogen application rate.

Soil phosphorus(P)cycle are varied in different land use soils.The transformation of soil organic P by hydrolyzing by enzymes is an important process in soil P cycling.The exogenous carbon(C)and nitrogen(N)application can influence on the biological process of soil P,which could play a key role in improving soil P bioavailability.In order to study the effects of exogenous C and N on soil organic P and extracellular enzyme activities in different land use soils,four soils from greenhouse vegetable field,grain field,grassland and forest were collected to conduct the incubation experiment.For each soil,four treatments were designed,including control(CK),glucose(G,500 mg/kg soil),potassium nitrate(N,300 mg/kg soil),glucose and potassium nitrate(GN,500 mg/kg glucose soil and 300 mg/kg potassium nitrate soil).The results showed that the soil organic P in greenhouse vegetable field and forest was increased after adding carbon source,increased by 89.7%,40.6%,respectively,compared to control treatment;with the addition of nitrogen sources,the available P in greenhouse vegetable soil increased by 14.2%,while that in forest soil decreased by 14.0%;compared to control treatment,the activity of alkaline phosphatase in grassland and forest soil decreased by 35.9%,25.5% with the input of carbon source,while that in greenhourse vegetable field and grain field soil had no significant effect;compared to control treatment, the β-glucosidase activity of four soils were increased by adding C and N, and the difference was significant in greenhouse vegetable field and grassland soil; based on the addition of carbon source,N addition reduced the cumulative release of CO₂ in grassland and forest soils by 19.7%,16.5%,respectively,but had no significant effect on that of greenhouse vegetable field and grain field soil.Therefore,in greenhouse vegetable field and grain field soil,the soil extracellular enzyme activity increased significantly after the application of exogenous carbon and nitrogen,and the mineralization of organic phosphorus into inorganic phosphorus was more.The content of soil organic carbon was the main factor affecting the mineralization of organic phosphorus in soil;in grassland and forest soil,the application of exogenous carbon and nitrogen reduced the activity of alkaline phosphatase and slowed down the mineralization process of organic phosphorus,so the activity of phosphatase was the main factor affecting the mineralization of organic phosphorus in the soil.

In order to explore the effects of different planting densities and potassium(K)application rates on dry matter accumulation and translocation,yield and K use efficiency of maize in the typical black soil region of Northeast China,the two-year continuous located experiment was studied the effects of different planting densities(D1:5.5×10⁴ plants/ha,D2:7.0×10⁴ plants/ha and D3:8.5×10⁴ plants/ha)and K application rates(K0,K40,K80,K120 and K160)on dry matter accumulation and translocation,K use efficiency and yield of maize in Gongzhuling City of Jilin Province.The results showed that there was a significant or extremely significant interaction between planting density and K application rate on dry matter accumulation of maize.The maximum and average accumulation rates of dry matter in D2K120 treatment were at the highest values,and the translocation amount and contribution rate of dry matter remained at higher levels.K recovery efficiency(REK),agronomic efficiency(AEK)and partial factor productivity(PFPK)at the same planting densities decreased with increasing K application rate,and the values reached the highest in D2 under the same amount of K application.Under the same K application rate,the maize yield in D2 was at the highest value.The average yields in two years under D2 were increased by 6.9%,3.0% than D1 and D3,respectively.At the same density,maize yield was significantly improved due to K fertilizer application.Among them,the yield increasing was no longer significant exceeding 80 kg/ha of K application rates under D1,and it was no longer significant exceeding 120 kg/ha of K application rates under D2 and D3.According to fitting a linear-plateau model,the appropriate ranges of K application rates were 72-80 kg/ha,104-115 kg/ha,105-116 kg/ha under D1,D2 and D3,respectively.Under the condition that K application rate in D2 was increased by 44.5% than that in D1 and was equal to that in D3,the maize yield in D2 was increased by 9.8%,3.2%,and REK was increased by 4.1,4.9 percentage points than D1 and D3,respectively.In conclusion,the planting density of 70 000 plants/ha and K application rate of 104-115 kg/ha are appropriate in the typical black soil region of Northeast China.

Partial substitution of chemical fertilizer with organic fertilizer is being increasingly recognized as a promising approach for achieving sustainable agriculture.This paper explores the proportion of organic fertilizer substitution nitrogen fertilizer,physiological basis for stable yield after substitution nitrogen fertilizer,and the effect of spraying liquid nitrogen after substitution nitrogen fertilizer in North China,in order to provide a basis for the technology of reducing nitrogen fertilizer and increasing yield and efficiency of winter wheat in this region.Field experiments of the following eight treatments were conducted in Ningjin,Hebei from 2020 to 2022:T1,non-nitrogen,application of chemical P and K fertilizer alone;T2,application of chemical N,P and K fertilizer alone;and T3- T7,substitution of 20%,40%,60%,80%and 100% the chemical N rate of T2 with organic fertilizer,respectively;T8,substitution of 100% chemical N rate of T2 with organic fertilizer,and spraying liquid nitrogen fertilizer at the erecting stage.The results showed that the organic fertilizer substitution rate of 29.5%-66.7% and the 100% substitution rate+liquid nitrogen treatment had higher wheat yield,and their yield was comparable to the CK.Under this fertilization condition,the leaf area index and leaf SPAD value were also higher at most stages,which was the physiological basis for stable yield after replacing chemical fertilizer with organic fertilizer.When the organic fertilizer substitution rate was greater than 40%,the wheat grain quality was higher,especially when the organic fertilizer substitution rate was 40%,the stability time,tensile area,and maximum tensile resistance were increased by 17.8%,23.5%,and 9.1%,respectively,compared to the CK.The nitrogen efficiency indicators of the CK,40% substitution rate,and 100% substitution rate+liquid nitrogen fertilizer treatments mostly performed better,with higher nitrogen uptake of grain,nitrogen fertilizer efficiency and nitrogen uptake efficiency.Substitution of chemical fertilizer with organic fertilizer significantly increased the nitrate nitrogen content in soil 0-80 cm from the erecting to the filling stage and 0-60 cm at the mature stage,resulting in a phenomenon of surface accumulation of soil nitrate nitrogen.The higher the replacement rate of organic fertilizer,the higher the nitrate nitrogen content in this layer of soil.Replacing nitrogen fertilizer with organic fertilizer could significantly reduce the nitrate nitrogen content of 80-100 cm soil in the mature stage,thereby reducing the risk of nitrogen leaching in the rainy season.Based on the above conclusions,the treatment of 40% substitution rate and 100% substitution rate+liquid nitrogen fertilizer had excellent wheat yield,quality,and nitrogen efficiency,with significant benefits.

It aimed to research the variation of mineral elements in the maize grain under the nitrogen(N)and zinc(Zn)fertilization,in order to provide scientific references for N and Zn application in the maize production.In the field plot experiment,two varieties including ZD958 and GSY66 were fertilized with three N rates(90,180 and 225 kg/ha)and four Zn treatments(no Zn,spraying Zn of 1∶1 at seedling stage and jointing stage,spraying Zn of 1∶1 at jointing stage and flare opening stage and spraying Zn at flare opening stage),to analyze the effects of N and Zn fertilization on the maize grain yield and mineral elements concentration and accumulation.The results showed that grain yield was significantly decreased,while Ca,Cu,Fe and Zn concentration as well as Cu and Fe accumulation were significantly increased when the N rate was more than 180 kg/ha.N and P,K,Mg concentration achieved the highest and lowerest values respectively under the 180 kg/ha N treatment.Spraying Zn of 1∶1 at jointing stage and flare opening stage and at flare opening stage only could significantly improve the yield,N and Zn concentration and N,Mg,Zn,B and Na accumulation,but decrease the P,K,Ca,B and Na concentration.Relative to GSY66,the grain yield of ZD958 was significantly increased by 19.3%,and K and Fe concentration and K,Ca,B and Na accumulation were also significantly increased.Grain yield showed extremely significantly negative correlation ship with most mineral element concentration.The positive correlationships among Ca,Mg,Cu,Mn,Fe,Zn and B were significant or extremely significant,expect for Ca and Mg,Zn.The linear regression relationships between grain Zn concentration and N,Mg concentration were significant or extremely significant.To sum up,applying 180 kg/ha N and spraying 4.5 kg/ha Zn of 1∶1 at jointing stage and flare opening stage could increase maize grain yield,N and Zn concentration and mineral elements accumulation,synchronously achieve the high yield and mineral nutrition,and are recommended to promote in maize production.

In order to effectively improve the 1000-grain weight of winter wheat,explore the effect of different drip irrigation and fertilization frequency on grain filling and mature grain shape of medium strong gluten wheat in the Huang-Huai-Hai wheat region,under the field experimental conditions,different winter wheat varieties with medium strong gluten were selected as experimental materials,a comparative experiment was carried out on different drip irrigation fertilization frequency(2,3,4 times,respectively represented by DF2,DF3,DF4)and traditional irrigation fertilization(CK)under 210 kg/ha of total nitrogen application(urea form)and 120 mm of total irrigation.The results showed that there were significant or extremely significant correlations between grain shape(except length and roundness),key grain filling parameters(V_mean,V_max,V₂,M₂)and 1000-grain weight through correlation analysis.Drip irrigation increased V_mean (average filling speed),V_max (maximum filling speed),V₂ (grain filling speed in rapid growth period),and M₂ (grain accumulation in rapid growth period).Compared with two times of topdressing with water and fertilizer(DF2),after three water and fertilizer applications(DF3),T_max,V_mean,V_max,V₂,M₂,and grain area all increased,and after four water and fertilizer applications(DF4),T_max,T₂,M₂ had improved.Compared with DF2,the length,width,thickness,roundness,and grains area increased with the frequency of fertilization(DF3 and DF4),the width and grain area of DF3 reached a significant level,and the thickness of DF4 reached a significant level,reducing the vertical and horizontal.The sieving equivalent of 2.2-2.5 mm was significantly reduced,and the sieving equivalent of >2.8 mm was increased,and the grains were more plump.Compared with border irrigation,the grains of DF3 and DF4 were also more plump.In conclusion,in wheat production,it is very important to increase the frequency of fertilization through drip irrigation to optimize the development of spike grains and improve grain weight.

To explore efficient irrigation strategies to reduce irrigation amount and improve crop water productivity to alleviate water scarcity in the Huang-Huai-Hai Plain winter wheat region of China. A split-plot field experiment was conducted to investigate the effects of surface drip irrigation(DI)and subsurface drip irrigation(SDI)systems on wheat yield,soil water extraction,evapotranspiration(ET),and water use efficiency(WUE).The DI and SDI systems consisted of three irrigation schedules(50%-60%,60%-70%,and 70%-80% of field capacity;hereafter,W₅₀,W₆₀ and W₇₀,respectively).The SDI treatment decreased the proportion by 11.8%-21.8% of soil water extraction in the 0-0.8 m soil layers while increased the amount by 28.4%-29.8% of soil water extraction in the 0.8-1.6 m soil layers for the whole growth period.The soil evaporation and irrigation amount of SDI were 23.1%,8.9% lower than that of DI on average,respectively.Although the transpiration rate did not differ significantly between SDI and DI after anthesis,the net photosynthetic rate(P_n)and leaf area index were higher in the SDI treatment than those in the DI under W₅₀ and W₆₀ conditions(deficit irrigation).As a result,the SDI treatment increased the yield by 14.5%-29.3% and WUE by 13.9%-25.9% under deficit irrigation conditions as compared to DI.Compared to DI, SDI decreased P_n and soil water extraction in the upper soil layers significantly under W₇₀ condition due to more soil water stored below 0.8 m soil layer,and resulted in yield reduction by 4.1%-8.9%.SDI with W₆₀ can extract more soil water from subsoil and regulate the photosynthetic characteristics of winter wheat,thereby improving yield and WUE.

In view of the problems of excessive input of nitrogen(N)fertilizer,serious nitrogen loss and soil N accumulation,and hard to popularize controlled-release urea(CRU)because of its high cost,this research,based on the field experiment including six crop growing seasons over three years,explored the application effect of combined CRU with urea under the condition of reduced N rate in winter wheat-summer maize rotation and aimed for optimizing the N application rate under applying the optimized blending application ratio of CRU and urea,so as to provide the technical references for reducing chemical N fertilizer input,increasing its use efficiency and generalizing CRU.The experimental design consisted of six treatments:CK(No N application),FH(urea with 270-240 kg/ha N application on winter wheat and summer maize respectively;50% of the total N applied once and 50% dressing).For N1,N2,N3 and N4 treatments, mixture of CRU and urea(controlled release nitrogen accounting for 40% of the total nitrogen content) was applied once before planting at 243,216,189 and 162 kg/ha respectively for winter wheat,and was applied at 216, 192, 168, and 144 kg/ha with controlled release nitrogen accounting for 30% respectively for summer maize.The results showed that:compared with FH,only N1 increased the yield and net profit of winter wheat and summer maize for three consecutive years.For winter wheat,N1 increased significantly the yield by 4.0%,5.4% in 2017-2018 and 2019-2020,respectively,and still increased the yield by 1.6% even in 2018-2019 that the yields of other treatments were decreased.N1 also increased significantly summer maize's yield by 10.9%.In addition,after harvesting winter wheat and summer maize per year,amount of accumulation of inorganic N in 0-100 cm and 60-100 cm soil layer of N1 was significantly lower than that of FH, while the cumulative N use efficiency of N1 after 6 growing seasons of crop was increased by 11.3 percentage point.These results demonstrated that a mixture of CRU and urea (at a ratio of controlled release nitrogen accounting for 40% and 30% of the total nitrogen content for wheat and maize respectively)with a 10% reduction in N application rate compared to FH could be more beneficial to increase crop yield and nitrogen use efficiency, and reduce leaching of soil inorganic nitrogen in wheat-maize rotation system.

In order to alleviate continuous cropping obstacles and improve soil, to ensure sorghum raw grain production and sustainable agricultural development. The long-term located experiment of continuous cropping sorghum was carried out in Dongbai base of Sorghum Research Institute of Shanxi Agricultural University from 2019 to 2020 to study the effects of tillage methods(traditional tillage,no tillage,rotary in autumn,subsoiling in autumn,deep ploughing in autumn,deep ploughing in spring)in fallow period on soil moisture,organic carbon content and yield of continuous cropping sorghum,aiming to find the suitable tillage method and time for increasing the yield of continuous cropping sorghum,and the mechanism of water conservation,carbon sequestration and yield increase so as to provide cultivation techniques and theoretical basis for the stable production of sorghum.The results showed that tillage in fallow period increased the soil organic matter in 0-20 cm soil layer in each growth period of sorghum,and increased the content of particulate organic carbon,light fraction organic carbon,heavy fraction organic carbon,readily oxidized organic carbon and dissolved organic carbon, and also increased soil water storage in 0-100 cm soil layer by 0.72-46.52 mm before sowing and soil water storage of 0-100 cm soil layer at each growth period, furthermore, the soil water before sowing continued to be used until jointing stage and it still was very effective even though much precipitation in the middle and late stages.Meanwhile,tillage in fallow period increased the yield by 4.75%-23.67% and the water use efficiency in the growth period by 19.09-29.19 kg/(ha·mm),especially the increased effect of deep ploughing in autumn was more significant.The correlation analysis showed that the yield of continuous cropping sorghum was significantly positively correlated with soil moisture and organic matter content,and the yield was more closely related to the soil moisture in the early growth stage if the base soil moisture level was higher and more closely related to the soil moisture in the middle and late stages if the base soil moisture level was lower and the precipitation in the middle and late stages was more.In short,deep ploughing in autumn of continuous cropping sorghum during fallow period was beneficial to increase the organic carbon content and promote the soil moisture conservation so that the moisture continued to be used at jointing stage,thereby increased yield and water use efficiency.

To reveal the application effect of controlled release urea in table grape(Shine muscat),and screen out the optimum application amount,a field experiment(2018-2019)was conducted to study the effects of nitrogen(N)reduction combined with polyurethane coated urea on the yield,photosynthetic characteristics and quality of table grapes,and to explore the relationship between chlorophyll content at different leaf positions and quality traits.The results of this study can provide scientific theoretical basis for the cost-saving and efficient utilization of N fertilizer in the cultivation of table grape.The results showed that:compared with the conventional fertilization treatment,the yield of table grape were increased by 10.67%-32.91%,under 0-30% N reduction combined with coated urea treatment,while reduced by 5.79% under 40% N reduction combined with coated urea treatment.Among them,suitable N reduction combined with controlled release fertilizer for table grape had better effect on yield and income increase than conventional fertilization.With the decrease of N application rate combined with coated urea,the yield and net photosynthetic rate of table grapes increased first and then decreased.Correlation analysis showed that there was a significant positive correlation between the mean value of SPAD of functional leaves at the expansion stage and the quality traits(soluble solid,total sugar,vitamin C,sugar-acid ratio and solid-acid ratio),but a significant negative correlation between SPAD value and total acid.In general,N reduction combined with coated urea treatment was beneficial to the formation of yield component,increased SPAD value and net photosynthetic rate of functional leaves at the puffing stage,effectively expand fruit grains,promoted the increase production,saved fertilizer and increased efficiency of table grapes,and improved the food quality of table grapes.The N reduction of 10%-20% combined with coated urea treatment had the best effect.

In order to investigate the effects of chemical fertilizer reduction and combined application of organic fertilizer on soil microbial quantity,nutrient content,eggplant yield,quality and water use efficiency in Hexi oasis,the field experiments of seven different treatments were carried out in 2019 and 2020 with purple long eggplant Tianlong 8 as the test material.Seven treatments were set up,including 100% common chemical fertilizer(FH),80% common chemical fertilizer+20% organic fertilizer(FE),60% common chemical fertilizer+40% organic fertilizer(FS),40% common chemical fertilizer+60% organic fertilizer(FF),20% common chemical fertilizer+80% organic fertilizer(FT),100% organic fertilizer(FZ)and no fertilizer control(CK).The changes of soil microbial quantity,nutrient content and yield in 0-20 cm after eggplant harvest were analyzed.The results showed that chemical fertilizer reduction combined with organic fertilizer could increase the number of bacteria,fungi,actinomycetes and the contents of total nitrogen,total phosphorus,total potassium and organic matter in soil.Among them,60% chemical fertilizer+40% organic fertilizer had the best improvement effect,followed by 80% chemical fertilizer+20% organic fertilizer.The combined application of pure chemical fertilizer had little effect on the growth dynamics of eggplant,but the combined application of organic fertilizer could significantly promote the nutrient absorption of eggplant,increase plant height,stem diameter and leaf area index,and regulate the yield components,laying the foundation for high yield of eggplant.Chemical fertilizer reduction combined with organic fertilizer can promote the distribution of eggplant photosynthetic products to fruit and improve eggplant yield.The economic yield of 60% chemical fertilizer+40% organic fertilizer treatment was the highest(42 716.15 kg/ha),followed by 40% ordinary chemical fertilizer+60% organic fertilizer(41 922.06 kg/ha)and 80% ordinary chemical fertilizer+20% organic fertilizer(40 302.74 kg/ha),which were 53.64%,50.78% and 44.96% higher than CK.Chemical fertilizer reduction combined with organic fertilizer can improve the water and heat status of soil tillage layer and improve the water use efficiency of eggplant.The water use efficiency of FS was the highest(10.46 kg/m³),followed by FF(10.37 kg/hm³)and FT(9.79 kg/hm³),which was 47.53%,46.19% and 38.08% higher than that of CK.Therefore,considering the soil environment,yield and water use efficiency,the best recommended treatment is chemical fertilizer and organic fertilizer is 60%+40% organic fertilizer.

The NPF transporter family plays an important role in plants transporting nitrate nitrogen.To reveal the sequence characteristic of NPF genes,the DNA and cDNA sequences of the nitrogen transporter CsNPF5 gene of tea plants were amplified by using PCR amplification,with full-lengths of 2 096,1 440 bp,respectively.Sequence analysis suggested that the gene contained three exons and two introns,with an open reading frame(ORF)of 1 440 bp,encoding 479 amino acids,having a relative molecular mass of 53.12 ku,an isoelectric point of 7.13 and a PTR2 Pfam domain at the N-terminal end of the encoded protein;subcellular localization analysis indicated that the encoded protein was localized in the cytoplasm;sequence alignment result showed that the CsNPF5 protein had high homology with the Chinese kiwifruit NPF protein,with a similarity of 79.54%;cluster analysis indicated that CsNPF5 and its homologous proteins were classified into three evolutionary branches,and CsNPF5 clustered into the same branch with the homologous protein NPF18 from Chinese kiwifruit.Meanwhile,the qRT-PCR analysis showed that the expression of CsNPF5 was differentially up-regulated in leaves under 0-48 h of nitrogen treatment;up-regulated expression abundance of gene responded faster with increasing NO₃^- concentration;the peak expression of CsNPF5 in tea leaves appeared after 24 h at 2 mmol/L NO₃^- treatment,which indicated that the gene expression was induced by nitrogen.

WRKY transcription factors act important regulators in plant response to low phosphorus.Buckwheat performs well in under-fertilized soils with higher phosphorus use efficiency.Taking tartary buckwheat as experimental materials,this study aims to explore the possible regulatory roles of WRKY genes in phosphorus starvation response of buckwheat.The entire coding sequence(CDS)of FtWRKY6 gene was cloned from RNA samples generated from roots treated by low phosphorus using reverse transcription PCR.The obtained CDS of FtWRKY6 was 1 572 bp in length,encoded a polypeptide of 524 amino acid residues which consists of two conserved WRKY domain each with a zinc finger motif of CCHH,and belonged to the WRKY group Ⅰ.FtWRKY6 shared the highest identity(55.5%)at the amino acid level with Camellia sinensis CsWRKY24.Transient expression assay in protoplasts showed that FtWRKY6 protein was localized in nucleus.Yeast one-hybrid assay revealed that FtWRKY6 had transcription-activating activity.Real-time fluorescence quantitative PCR analysis showed that the expression of FtWRKY6 in roots was significantly induced by low phosphorus and three related hormones such as indole acetic acid(IAA),gibberellin(GA)and cytokinin(CTK).Taken together,FtWRKY6 possesses basic structural and biochemical characteristics as a putative transcription factor,and may be involved in low phosphorus response in roots possibly by crosstalk of IAA,GA and CTK signaling pathways.

Under the double cropping pattern in the North China Plain,based on the conventional application level of phosphorus,a phosphorus-deprived level without phosphorus fertilizer was adopted at the same time for three previous crops,corn,soybean and peanut,and then the soil nutrient concentration after previous crop harvesting and the grain yield and nutrient accumulation of winter wheat,the subsequent crop,were examined,to provide a proposal for crops planting in the North China Plain.The results showed that,for the soil nutrients after the previous crop harvesting,the soil total phosphorus concentration was higher in the previous soybean treatment without phosphorus fertilizer,and the concentration in peanut previous treatment was similar to that under conventional fertilizers;the soil available phosphorus content was higher overall in the previous peanut treatment;the soil nitrate and ammonium nitrogen concentrations were both highest in the previous soybean treatment.For post-crop wheat,wheat thousand grains weight,yield,seed N and P accumulation and N fertilizer bias productivity were all higher in the previous peanut treatment without phosphorus fertilizer.The previous peanut treatment increased by 0.60%,6.19%,15.46%,18.11% and 6.21%,respectively,compared to the previous maize treatment,and increased by 2.18%,7.30%,17.66%,13.40% and 7.30%,respectively,compared to the previous soybean treatment.In summary,in order to ensure soil nutrient balance,peanut was selected as a suitable previous crop in summer before winter wheat as a better model for crop mix in the southern two maturity zones of the North China Plain at low phosphorus levels.

In order to explore the effects of different long-term (36 a)fertilizer treatments on characteristics of soil acid buffering capacity at different soil layers (0—10 cm and 10—20 cm)under the double-cropping rice field in Southern of China,four different fertilizer treatments were set up:without any fertilizer input as a control(CK),chemical fertilizer alone (MF),rice straw and chemical fertilizer (RF),and 30% organic manure and 70% chemical fertilizer (OM).Soil acid neutralizing capacity(ANC),acid buffering capacity(ABC),instant acid buffering capacity(IAC),ammonium nitrogen($\text{NH}_{4}^{+}$-N),nitrate nitrogen($\text{NO}_{3}^{-}$-N)contents,and its relationship between soil acid buffering capacity and soil physicochemical properties were analysis.This result indicated that soil ANC,ABC and IAC at soil 0—10 cm and 10—20 cm layer in the double-cropping rice field with MF,RF and OM treatments were increased.The order of soil ANC,ABC and IAC at soil 0—10 cm and 10—20 cm layer in paddy field with all fertilizer treatments showed OM>RF>MF>CK.Compared with CK treatment,soil ANC and ABC at 0—10 cm and 10—20 cm layer in paddy field with OM treatment increased by 36.78%,33.18% and 18.67%,17.84%,respectively.Soil IAC at 0—10 cm and 10—20 cm layer in paddy field with OM treatment increased by 15.22% and 14.02%,compared with CK treatment,respectively.This result indicated that soil $\text{NH}_{4}^{+}$-N content at 0—10 cm and 10—20 cm layer in paddy field with MF treatment were significantly higher than that of RF,OM and CK treatments.Soil $\text{NH}_{4}^{+}$-N content at 0—10 cm and 10—20 cm layer in paddy field with MF treatment increased by 48.15% and 51.09%,compared with CK treatment,respectively.This result showed that soil $\text{NO}_{3}^{-}$-N content at 0—10 cm and 10—20 cm layer in paddy field with OM treatment were significantly higher than that of MF,RF and CK treatments.Soil $\text{NO}_{3}^{-}$-N content at 0—10 cm and 10—20 cm layer in paddy field with OM treatment increased by 204.73% and 161.94%,compared with CK treatment,respectively.Soil ANC,ABC,IAC,$\text{NH}_{4}^{+}$-N and $\text{NO}_{3}^{-}$-N contents at 0—10 cm layer were obvious higher than that of 10—20 cm layer in paddy field under the same fertilizer treatment condition.It had significantly positive correlation between soil ANC,ABC,IAC and soil organic carbon,total nitrogen contents,electrical conductivity in paddy field.Meanwhile,there had extremely significantly positive correlation between soil ANC,ABC,IAC and soil pH,cation exchange capacity in paddy field.As a result,it was effective practices for increasing soil acid buffering capacity at plough layer under the double-cropping rice field in Southern of China by combined application of rice straw or 30% organic manure with chemical fertilizer managements.

It explored the ratio of organic fertilizer replacing nitrogen fertilizer in the piedmont plain of Hebei Province,in order to provide a basis for reducing the amount and increasing the efficiency of nitrogen in wheat in this area.Field experiments were carried out in Boyuan farm in Yongnian,Hebei Province for two consecutive years,and five organic and inorganic fertilizer combination treatments were set up.The results showed that organic fertilizer instead of 20% and 40% chemical fertilizer could significantly improve the number of grains per spike and yield.Compared with the high nitrogen and saving nitrogen treatment of single chemical fertilizer application,the yield increased by more than 4.0%,and the number of grains per spike increased by 3.6—5.6.Most of the grain quality indexes for organic fertilizer instead of 20% and 40% chemical fertilizer treatment,and saving nitrogen treatment were better,and the stabilization time increased by 2.2—2.7 min,the tensile area increased by 10.5—17.5 cm²,and the maximum tensile resistance increased by 28.0—75.5 EU.Various nitrogen efficiency indicators of treatment for organic fertilizer instead of 20% were higher.The nitrogen fertilizer efficiency,nitrogen utilization efficiency,and nitrogen harvest index increased 109.3%,9.3% and 11.3% respectively compared with high nitrogen treatment,and 6.9%,8.5% and 8.3% respectively compared with the saving nitrogen treatment.When organic fertilizer replaced chemical fertilizer in different proportions,nitrate nitrogen in 0—20 cm soil appeared "surface accumulation",and the content of nitrate nitrogen increased,which was more than 38.5% higher than that of the saving nitrogen treatment.The nitrate nitrogen in 20—40 cm soil was significantly higher for the saving nitrogen treatment and the high nitrogen application treatment.Organic fertilizer instead of 20% nitrogen fertilizer treatment had the best yield and grain quality,significantly improve the nitrate nitrogen content in 0—40 cm soil,improve the nitrogen absorption and utilization of wheat,and finally obtain higher environmental benefits.

To explore the abundance of Gibberella zeae and the composition and diversity of fungal communities in spring wheat belt of the Northeast, bulk soil samples were collected under four crop rotation patterns, such as wheat-wheat-potato (T), wheat-wheat-silybum marianum (MT), wheat-wheat-oilseed rape (R), wheat-wheat-sugarbeet (S), and wheat for three years (W) was used as control. The Illumina MiSeq was used to sequence the ITS amplicons of the strains. The data showed that the number of fungal OTUs in W, T, MT, R and S was 389, 362, 390, 471 and 438, respectively. In the R and S rotation pattern, Chao1 were increased 11.08% and 8.59% respectively, compared with wheat continuous cropping, indicating that the rotation of silybum marianum, oilseed rape and sugarbeet with wheat increased the abundance of fungi genus. Among the five planting patterns, Shannon and Simpson in MT were the highest, revealed that the diversity of fungal communities in MT was more enriched. The similarity cluster analysis of fungal community structure showed that the four rotation patterns clustered into one branch. Under the four cropping rotation patterns, the abundance of basidiomycota increased while that of Zygomycota decreased. We also found that the relative abundance of Gibberella zeae decreased by 16.67%, 50.00% and 83.33% in R, S and MT, respectively, while the abundance of friendly genus were remarkably increased. However, the relative abundance of Gibberella zeae was increased significantly in the T pattern. Based on the above research results and the local planting structure, it is suggested to plant silybum marianum, sugarbeet and oilseed rape rotation with wheat to reduce the hazard of wheat scab.

The purpose of this study was to analyze the differential expression of FABP2 in different tissues of DLY fattening pigs fed different proportions of Zanthoxylum seeds instead of some corn,and to find the key gene for intramuscular fat deposition;at the same time,the sequence of the coding region of FABP2 in DLY fattening pigs was cloned and analyzed by bioinformatics methods.A total of 288,90-day-old Duroc Landrace Yorkshire fattening pigs(33 kg)were randomly divided into 4 groups with 4 replicates and 18 pigs in each replicate;the control group was fed the basal diet and the test group was fed Zanthoxylum seeds instead of corn in the diet at 2.5%(test group Ⅰ),5.0%(test group Ⅱ)and 7.5%(test group Ⅲ),respectively,for 7 d in the pretest and 100 d in the test period.PCR was used to detect the relative expression of FABP2 in different tissues of the test groups,and the coding region of FABP2 in DLY fattening pigs was also cloned,and bioinformatics analysis software was used to predict the physicochemical properties,structural domains and phosphorylation kinase sites of FABP2 protein.The results showed that FABP2 was differentially expressed in all tissues,with significantly higher expression in jejunum and liver.Compared with the control group,FABP2 was significantly down-regulated in heart,lung,kidney,duodenum,jejunum and cecum tissues in each test group;FABP2 was significantly up-regulated in spleen and ileum tissues in test group Ⅱ and test group Ⅲ;FABP2 was significantly up-regulated in liver,colon,rectum and dorsal muscle tissues in test group Ⅰ,indicating that the addition of Zanthoxylum seeds in the diet had a significant effect on the expression profile of FABP2 gene in DLY fattening pigs.In this experiment,the full length(399 bp)of the coding region of FABP2 was successfully cloned and identified,encoding 132 amino acids,with two missense mutations;FABP2 protein was an acidic stable non-secretory protein with a secondary structure consisting mainly of extended chains and random coils,containing a Lipocalin-FABP2 superfamily conserved structural domain and three disordered regions.

In order to elucidate the effect of decreasing nitrogen rate and increasing planting density on photosynthesis,dry matter accumulation and transportation characteristics and yield of sorghum,a field experiment was conducted using the waxy sorghum hybrid Jinyunuo 3 as experimental material in 2017-2018.Four treatments of normal nitrogen application with normal planting density(CK),normal nitrogen application with dense planting density(T1),reducing nitrogen application with normal planting density(T2),and reducing nitrogen application with dense planting density(T3)were set to investigate the chlorophyll content(SPAD)and leaf area index(LAI)at heading stage,dry matter accumulation and transport characteristics,yield and yield components of sorghum. The results showed that,compared with CK,the SPAD of the top three leaves at heading stage and LAI were decreased by reducing nitrogen application,while the SPAD was decreased by dense planting,but LAI was increased significantly.The dry matter accumulation of sorghum population increased with the development of growth process and increased rapidly after jointing stage and reached the maximum in maturity stage.Reducing nitrogen application improved dry matter translocation efficiency of leaf and stem+sheath before anthesis and contribution to grain,but decreased dry matter accumulation of population,dry matter accumulation after anthesis and its contribution to grain.Increasing density significantly boosted dry matter accumulation of population,dry matter translocation of leaf and stem+sheath before anthesis,as well as their transportation efficiency and contribution to grain,but reduced the contribution of dry matter to grain after anthesis. The ear weight and 1000-grain weight were reduced by dense planting,but the yield increased significantly. The ear weight and 1000-grain weight were decreased by reducing nitrogen application,but the yield of normal density decreased while that of densification increased significantly. Compared with CK,the 2-year average yield of T1 and T3 treatments were significantly higher by 8.43% and 7.92% respectively,and there was no significant difference between the two treatments. In conclusion,the planting mode of Jinyunuo 3 in Chongqing was reducing nitrogen application with dense planting,that was,applying nitrogen 150 kg/ha and density 12.75×10⁸ plants/ha. It was beneficial to realize high yield,high efficiency and nitrogen saving cultivation of sorghum.

To reveal the effects of long-term fertilization on carbon sequestration potential and crop yield of fluvo-aquic soil in Shandong Province,taking the winter wheat-summer maize rotation system as the research object,carbon sequestration characteristic and its yield effect of fluvo-aquic soil were explored by long-term fertilization of 28 a.The experiment adopted split-zone design.The main treatments included single inorganic fertilizer treatment and organic and inorganic fertilizer treatment.The treatments in the fertilizer area were CK,N,NP,NK,PK,NPK,N₁₅PK,N₂₅PK.The treatment in the organic fertilizer area was based on the treatment in the chemical fertilizer area,and the same amount of organic fertilizer was added respectively.The results showed that the cumulative carbon input and carbon sequestration rate of the organic fertilizer treatment were 2.47,4.29 times higher than those of the chemical fertilizer treatment,respectively.Soil organic carbon(SOC)storage in the organic fertilizer treatment was 155.6-193.2 t/ha,and the carbon sequestration rate was 0.25-2.18 t/(ha·a).SOC storage in the chemical fertilizer treatment was 39.5-100.5 t/ha,and the carbon sequestration rate was 4.15-5.49 t/(ha·a).Both the chemical fertilizer area and the organic fertilizer area had the highest carbon storage and the fastest carbon sequestration rate in the increment NPK treatment.SOC increased linearly with the input of exogenous accumulated carbon.The storage capacity of SOC was 18.4%-20.6% when the input amount of exogenous carbon was less than 120 t/ha.The storage capacity of SOC was 11.5% when the input amount was 120-200 t/ha.The soil carbon sequestration efficiency was 11.7% when the cumulative input of exogenous carbon was less than 100 t/ha.The soil carbon sequestration efficiency was 4.3% when the cumulative input of exogenous carbon was 100-200 t/ha.There was a very significant correlation between SOC content and wheat and maize yields.When soil organic carbon is increased by 1 g/kg in fluvo-aquic soil,the yield of wheat and maize can be increased by 208.4,184.8 kg/ha,respectively,and the total crop yield can be increased by 414.5 kg/ha.It is recommended that the cumulative organic carbon input amount was 150 t/ha under the condition of ensuring soil fertility and crop yield.

In order to reveal the effects of the amount of nitrogen fertilizer and the ratio of basic application of nitrogen fertilizer to top application at jointing stage on the yield,quality and nitrogen efficiency of weak gluten wheat,and to clarify the optimal nitrogen fertilizer management measures for weak gluten wheat,the weak-gluten wheat variety Emai 580 was selected as the test material,and the nitrogen fertilizer amount experiment and nitrogen fertilizer base topdressing experiment were set up.The nitrogen fertilizer amount experiment was set up with 5 treatments of 0,90,135,180,225 kg/ha,and 4 treatments of 10∶0,7∶3,5∶5 and 3∶7 were set in the nitrogen fertilizer base topping ratio experiment.Through the determination and analysis of wheat chlorophyll content(SPAD),leaf area index(LAI),yield,yield components,nitrogen utilization rate and quality under different treatments,it was clear that different nitrogen fertilizer management modes affect the yield,nitrogen fertilizer efficiency and quality of weak gluten wheat.The results showed that reasonable nitrogen fertilizer management could effectively improve the photosynthetic capacity of wheat,delay the decline of chlorophyll,increase yield and nitrogen use efficiency,and improve wheat quality.With the increase of nitrogen application rate,the wheat yield increased first and then decreased.The highest yield was 5 903.0 kg/ha when the nitrogen application rate was 180 kg/ha and the base-dressing ratio was 7∶3.Under the same fertilization rate,nitrogen absorption and utilization rate,partial factor productivity of nitrogenand nitrogen agronomic efficiency of wheat increased first and then decreased with the increase of top dressing ratio.When the base-to-chasing ratio was 7∶3,the three indicators all reach their maximum values:37.6%,32.8 kg/kg,and 12.0 kg/kg.Different nitrogen fertilizer management modes had obvious effects on wheat quality indexes.The grain crude protein content,wet gluten content and stabilization time all showed an increasing trend with the increase of nitrogen fertilizer dosage and the backward shift of nitrogen fertilizer.Based on various indicators,the nitrogen application rate of 180 kg/ha and the base-to-dressing ratio of 7∶3 were the optimal nitrogen fertilizer management mode for the synergy of yield,quality and nitrogen use efficiency of weak gluten wheat.

Appropriate reduction of nitrogen fertilization is an important way to deal with serious nitrogen loss and low fertilizer-nitrogen use efficiency in field ecosystem in China.However,it is unclear whether reducing nitrogen fertilizer input can maintain the yield of densely planted cotton after oil.Taking the post oil direct seeding cotton field in Dongting Lake area as the research object,compare the yield,photosynthetic characteristics of main stems and leaves,nitrogen use efficiency and other differential characteristics of cotton under two-year nitrogen fertilizer reduction and deep application,and analyze the feasibility of nitrogen fertilizer reduction and deep application,so as to provide a scientific basis for the formulation of fertilization management measures in direct seeding cotton fields after oiling.From 2018 to 2019,the deep application test of nitrogen fertilizer reduction was carried out in Maowan base of Hunan Institute of Cotton Science,Changde City,Hunan Province.Five nitrogen fertilizer application treatments(0,90,180,270,360 kg/ha)and two deep application treatments(5,15 cm)were set up.Samples were taken during the main growth period of cotton to measure the net photosynthetic rate,soluble sugar and starch content of functional leaves of main stems,the aboveground plant biomass and NPK content of each part.To study the effects of deep application of nitrogen fertilizer reduction on the yield,photosynthetic characteristics,aboveground plant biomass,NPK accumulation and distribution of densely planted cotton after oil.With the increase of N-fertilizer application rate,the Pn,soluble sugar and starch content of functional leaves of cotton main stem and the accumulation of NPK in cotton plant increased first and then decreased in the middle and late stages,all of which were the highest at 270 kg/ha;the apparent utilization rate of nitrogen fertilizer,agronomic utilization rate,partial productivity and production efficiency are opposite;in addition,under the same nitrogen application rate,the indicators of deep 15 cm treatment were higher than that of shallow 5 cm treatment.Reasonably reducing the amount of nitrogen fertilizer combined with deep application treatment is conducive to the accumulation and balance of biomass in vegetative and reproductive organs of cotton plants,as well as the absorption and distribution of nitrogen,phosphorus and potassium,so as to promote the improvement of yield and quality.Based on the dense planting mode after oiling,it is recommended that the amount of nitrogen applied to cotton should be 180-224 kg/ha and the depth of fertilization should be 15 cm.

In order to explore the storability of Chinese cherry fruit,reduce the decay rate of post harvest fruit and prolong its storage life. Chinese cherry Black pearl was sprayed with CaCl₂,amino acid calcium and sugar alcohol calcium after flowering. The internal and external quality of post harvest fruits during storage and several protective enzymes were studied,and the most suitable calcium fertilizer and its concentration were selected.The results showed that:with the extension of storage time,cherry fruit hardness,100 fruit weight,soluble sugar,titratable acid,soluble protein,Vc,β-carotene decreased;the content of MDA and REC increased gradually;the activities of soluble solids,SOD,POD and PPO increased first and then decreased;the nutrient and water loss,PPO activity and MDA accumulation of cherry fruit treated with calcium fertilizer during storage were lower than CK;the activities of SOD and POD were higher than CK. Foliar calcium fertilizer improved the storage resistance of Black pearl cherry. The comprehensive evaluation of membership function showed that 1 500 times sugar alcohol calcium had the best effect on fruit preservation. Spraying calcium fertilizer before harvest could improve the hardness,quality and the activity of antioxidant enzymes of cherry fruit,so as to prolong the storage period of cherry.1 500 times sugar alcohol calcium can be popularized and applied in production.

In order to explore the application effect of a new type of biochar-based compound fertilizer prepared by low temperature carbonization of waste organic sulfuric acid,a pot experiment was carried out with Xiaoding bacunshen as the test carrot variety and saline fluvo-aquic soil as the test soil. A total of 11 treatments were set up with 5 kinds of compound fertilizers and their carbon-based compound fertilizer formula treatments,and the effects of 5 kinds of biochar-based compound fertilizer formulas on carrot yield and soil nutrient content were studied. Results showed different fertilization significantly promoted the increase of fresh weight of carrot fleshy roots. Among them,carrots treated with 12-6-10 sulfur-based compound fertilizer with 15% carbon content had the highest fresh weight of fleshy root biomass,with a fresh weight of 313.85 g/plant,and the 10-5-20 chlorine-based fertilization treatment had the lowest yield of carrots. In contrast,10-5-20 chlorine based compound fertilizer had the lowest carrot yield. Compared with common compound fertilizers,those 5 kinds biochar-based compound fertilizers had significant effects on the increase of fresh weight of carrot fleshy root,with the range of increase of 2.1%-11.3%,and increased the accumulation of nitrogen,phosphorus and potassium in different degrees. In addition,the soil available N,P and K supply could be maintained by applying biochar-based compound fertilizer with 15% reduction of N,P and K nutrient application,and soil nutrients were still significantly increased in some periods. Application of biomass sulfonated carbon fertilizer could reduce the soil pH at the early stage of carrot growth,but there was no significant difference in soil pH at the mature stage of carrot. In conclusion,compared with common compound fertilizer,the application of biomass sulfonated carbon fertilizer could reduce the soil pH,increase the accumulation of nitrogen,phosphorus and potassium of carrot and the soil available nitrogen,olsen phosphorus and available potassium supply,which was conducive to carrot yield increase.

To study the effect of soil water and fertilizer management mode on orchard in dryland area,and to provide support and basis for optimizing water and fertilizer management and realizing the best matching of water and fertilizer in apple orchard.Put into use the three main modes that include integrated water-fertilizer and plastic mulching(T1),ridge film rainwater harvesting + straw mulching in ditch(T2),use fertilizer gun to integrate the fertilizer and water(T3),and conventional tillage fertilization(T4)were used as the comparison where in apple orchards of Gansu Province Longdong area.Measure and analysis the contents that the soil organic matter and mineral nutrition,chlorophyll and nutrient content in leaves and fruit quality in apple orchard.In different water and fertilizer management modes of apple orchards in dryland area.The contents of soil organic matter,total nitrogen,alkali-hydrolyzable nitrogen,total phosphorus,available phosphorus and available potassium showed a decreasing trend with the increase of soil depth from 0 to 60 cm,while the decreasing range gradually decreased.The contents of organic matter and mineral nutrients in shallow soil(0-20 cm)were significantly higher than those in middle and deep soil(20-60 cm). The content of soil total K was higher in different modes and layers.The results showed that the soil nutrients were enriched in shallow layer and the soil potassium was rich.In young fruit stage,fruit expansion stage and fruit maturity stage of apple,the decrease rates of the soil total nitrogen,total phosphorus and total potassium were significantly lower than those of available nutrient that the alkali-hydrolyzed nitrogen,available phosphorus and available potassium.The absorption and utilization efficiency of the soil mineral nutrients were different with different water and fertilizer patterns,while the nutrient consumption degree was also different,especially in shallow soil. In 0-20 cm soil depth,the content of soil organic matter in T4 treatment which the young fruit stage and fruit expansion stage was significantly higher than that in other treatments,while it was significantly lower at the fruit maturity stage.This showed that the clear tillage management(CK)had a low capacity of soil fertilizer conservation and nutrient sustainable supply.Under different water and fertilizer management modes,the chlorophyll contents which the young fruit stage and fruit expansion stage varied greatly,and the chlorophyll a,b and total chlorophyll content of T3 were significantly higher than those at T1 and T4 at young fruit stage. However, there was no significant difference with T2.There was no significant difference that the mineral nutrient content in leaves between different modes and different periods.The contents of total nitrogen,phosphorus on a downward trend with the growth and development of apple.While the potassium content in leaves showed an upward-downward trend.The contents of the nitrogen,phosphorus and potassium in leaves were the lowest at fruit maturity stage.The soluble sugar,total sugar and solid acid ratio of T2 were significantly higher than those of other treatments. The content of VC in T2 was significantly higher than T4,but not significantly different from T1 and T3.The application of "ridge film rainwater harvesting + straw mulching in ditch" technology can significantly improve water and fertilizer utilization efficiency and fruit quality in apple orchard in dry farming area.

Provide scientific ecological planting and fertilization scheme for the cultivation of Alismaorientale(Sam.)Juzep.,and explore the effects of combined application of biological organic fertilizer and inorganic fertilizer on the agronomic properties and yield of A. orientale.In this study,the "3414" experimental design was used to investigate and analyze 13 agronomic characters and yield of A. orientale.It was found that organic fertilizer could significantly increase the number of blades;the combined application of organic fertilizer and chemical fertilizer can promote the growth of leaves and tuber expansion,and significantly improve the yield.The aboveground agronomic characters of A. orientale treated with 4(X₂Y₀Z₂),such as leaf number,leaf width,leaf dry weight and plant height,performed best.The agronomic characters of the underground part of A. orientale treated with 14(X₂Y₁Z₁)were more,such as fresh and dry weight of tubers,width and length of tubers,and the highest yield was 2 386 kg/ha.Through cluster analysis,it was found that the combined application of organic and inorganic fertilizers mainly affected the fresh and dry weight,yield,tuber width,tuber height,leaf length and leaf width of A. orientale.It was found that the yield and tuber width could be divided into the same kind of indicators,and there was a very significant positive correlation between them,with a correlation coefficient of 0.97.Therefore,the tuber width of A. orientale can be selected as a main agronomic character index for predicting yield and seed selection.Through the comprehensive evaluation of grey correlation degree and DTOPSIS Method,the best treatment is X₂Y₁Z₁, that is bio organic fertilizer 150 kg/ha,urea 420 kg/ha, calcium super phosphate 200 kg/ha, potassium sulfate (K₂SO₄≥51.0%) 240 kg/ha, zinc sulfate(ZnSO₄·7H₂O)7.5 kg/ha, boric acid(H₃BO₃) 9.5 kg/ha, ammonium molybdate((NH₄)₆Mo₇O₂₄·4H₂O)0.075 kg/ha.Based on the results of this study,the combined application of organic fertilizer and inorganic fertilizer can effectively promote the growth of A.orientale and increase it’s yield.

This pepper was to study the effects of distillers lee organic fertilizer on green Meitancuiya tea,so as to provide theoretical basis for the scientific application and popularization of distillers lee organic fertilizer.A field experiment was conducted to study the effects of distillers lee organic fertilizer(CK: no fertilizer;FP: farmers practice;JZ1: distillers lee organic fertilizer of 750 kg/ha;JZ2: distillers lee organic fertilizer of 2 250 kg/ha;JZ3: distillers lee organic fertilizer of 3 750 kg/ha;JZ4: distillers lee organic fertilizer of 9 000 kg/ha) on the yield,yield composition,quality and nutrient accumulation of tea.The results showed that the application of distillers lee organic fertilizer increased the yield of fresh tea by 2.58%-7.52%(2020)and 0.67%-11.92%(2021),the yield of dry tea increased by 5.18%-13.90%(2020)and 4.21%-19.62%(2021)compared to the FP treatment,with the highest yield in the JZ3 treatment.Application of distillers lee organic fertilizer increased the bud density and 100-bud weight of green tea,and also increased the amino acid content of green tea by 2.35%-12.60%(2021),and reduced the phenol-ammonia ratio,which was beneficial to improving the quality of green tea.Compared with the FP treatment,the application of distillers lee organic fertilizer increased the accumulation of nitrogen,phosphorus and potassium.The application of distillers lee organic fertilizer can increase the yield and quality of Meitancuiya tea,and 2 250-3 750 kg/ha can be recommended as the optimal application rate of distillers lee organic fertilizer for green tea cultivation and planting in Meitancuiya tea.

Potassium is one of the large amount of elements needed by plants. Potassium plays an important role in plant growth and development. However,there are problems of insufficient and low utilization rate of potassium fertilizer in agricultural production. It analyzed the research papers on potassium nutrition at home and abroad since 1965,and summarized the following five aspects. Firstly,it summarized the general situation of potassium,it summarized the general situation of potassium, distribution problem and lack of potassium resource in our country. Secondly,the nutritional function,stress resistance,yield and quality of potassium were summarized.Thirdly,the concept,principle and implementation method of potassium nutrition diagnosis were introduced,the importance of potassium nutrition diagnosis was emphasized,and the research status of potassium nutrition diagnosis in recent years was analyzed and summarized.Fourthly,the position of potassium absorption,the factors affecting potassium absorption and the ways and methods of potassium transport in plants are described successively,and several typical theoretical systems of how potassium plays a role in plants were discussed.Fifth,it focused on the genetic research of potassium nutrition. On the one hand,it summarized the genetic characteristics of potassium nutrition(the difference of plant potassium nutrition genotype is controlled by heredity;Potassium nutrition traits in plants are controlled by both single gene and multiple genes). On the other hand,recent studies on potassium nutrition heredity at molecular level were summarized. It was found that the studies on potassium nutrition heredity at molecular level focus on gene level and protein level. To sum up,summarizing the research status of potassium nutrition utilization and traits in plants in recent years from five aspects:the general situation and important role of potassium,diagnosis of potassium nutrition,absorption and transport of potassium,and heredity of traits of potassium nutrition. It is suggested to improve and breed new varieties by using modern biotechnology and the genetic characteristics of plants with low potassium tolerance.

In order to determine the effects of V.villosa Roth cultivation in apple orchard on soil microbial community structure,the high-throughput sequencing technology was used to analyze the microbial structure of V.villosa Roth cultivation soil in seven areas of Shandong Province and different phenological period of the same orchard,taking natural grass treatment as comparison.The correlation between microbial community structure and physicochemical properties of grass cultivation soil was analyzed.Results showed that,in seven sampled sites of Shandong Province,the relative abundances of Metarhizium in V.villosa Roth cultivation treatment were all higher than those in the control,and the difference was biggest in Dongying Area.The relative abundances of Fusariumin V.villosa Roth cultivation treatment of six sites were lower than those of the control,except for Zoucheng.The relative abundances of Gibberella in V.villosa Roth cultivation treatment of six sites were lower than those in the control,except for Rongcheng.In Zoucheng and Longkou,the relative abundances of Alternaria were lower than those of the control.Analysis of microbial community structure in different apple phenological stages of V.villosa Roth cultivation in the same orchard showed that,the relative abundance of Aspergillus in flowering stage soil was much lower than that of natural grass.The relative abundances of Fusarium and Aspergillus in fruit setting stage in V.villosa Roth cultivation treatment were lower than those of natural grass.The relative abundance of Bacillus in V.villosa Roth treatment was higher in fruit expansion stage.The relative abundance of Bradyrhizobium was higher in mature stage,while Gibberella,Cladosporium and Bipolaris were much lower than those of natural grass.Effects of V.villosa Roth cultivation in apple orchard on soil microbial community structure differed in different region and phenological stage.However,the relative abundance of beneficial bacteria in soil was increased,while that of pathogenic fungi was decreased,which was helpful to improve orchard soil micro-ecological environment and promote the healthy cultivation of fruit trees.

To provide a theoretical basis for the high-quality production and precise fertilization of Merlot grapes,through the determination of the mineral element content of each growth and different tissue parts,and the nutritional diagnosis and analysis based on the quality index formed by the phenolic substances in the fruit.The comprehensive quality index of fruit phenolics,namely CI value,was calculated by Topsis analysis method.By comparing the correlation between content of various mineral elements in different growth stages/ tissues and CI value,the nutritional diagnostic factors are determined.In order to provide a theoretical basis for the high-quality production and precise fertilization of Merlot grapes,high-CI vineyards were classified by CND method.The results showed that there was a significant synergistic and antagonistic relationship among the mineral elements in the leaves,petioles and fruits of the Merlot grapes.VS_F_N,MS_F_P,VS_F_K,VS_L_Ca,FBS_F_Mg,VS_F_Fe,FBS_L_Mn,MS_F_Zn,FBS_P_Cu,VS_P_B,FBS_L_Mo were selected as plant nutrition diagnostic factors.The quality index inflection point value of high-CI vineyards was 0.735 5,of which 7 orchards met this condition,accounting for 14.58% of the overall sample.According to the mineral element content range of Merlot plant within high-CI vineyards,the appropriate values of nutritional diagnostic factors were:N(8.85—11.81)mg/g,P(1.98—4.26)mg/g,K(14.97—20.70)mg/g,Ca(35.57—68.83)mg/g,Mg(3.69—15.51)mg/g,Fe(70.96—103.26)mg/kg,Mn(166.20—277.67)mg/kg,Zn(10.71—20.27)mg/kg,Cu(9.54—14.90)mg/kg,B(11.44—17.07)mg/kg,Mo(0.69—1.60)mg/kg.The nutritional diagnosis of high-CI vineyards showed that the K,Ca,Mn,and Mg in Merlot plants were on the low side.The obtain the highest fruit quality index as the goal,the recommended fertilizer rates per hectare were N 62.25 kg,P₂O₅ 46.50 kg,K₂O 0.00 kg,CaO 56.25 kg,and MgO 46.50 kg.Ca and Mg fertilizers should be applied in small amounts and multiple times;we should strengthen the management of water and fertilizer in the orchard to increase the absorption of K element by the tree.Through foliar spraying,the lack of Mn elements can be appropriately supplemented.

In order to explore the responses of kernel position effect of summer maize to plant density and its carbon and nitrogen metabolism characteristic,field experiments were conducted during 2020 and 2021 growing reasons at Dishang Experimental Station,Institute of Cereal and Oil Crops,Hebei Academy of Agriculture and Forestry Sciences. Three plant densities(PD1:60 000 plants/ha;PD2:75 000 plants/ha;PD3:90 000 plants/ha)were arranged,with the objectives to study the effect of plant density on grain filling and kernel weight ratio of inferior and superior kernel and its physiological characteristics of carbon and nitrogen metabolism. Compared with the superior kernel,the response of inferior kernel to plant density was more obvious,significant differences in grain-filling rate and kernel weight of inferior kernel were observed since 20—25 d and 30—35 d after pollination,respectively. As the plant density increases,the kernel weight ratio of inferior to superior kernel significantly decreased,PD3 decreased the kernel weight ratio of inferior to superior kernel by 8.45% on average,compared to that of PD1. The single plant dry matter accumulation significantly decreased as the plant density decreased,this was mainly due to the significant decrease of post-silking dry matter accumulation. The analysis of carbon and nitrogen metabolism of kernel showed that the increased plant density exacerbate the difference in starch and protein contents between inferior and superior kernels;and the increased plant density also exacerbate the difference in SPSase,ADPGase and GS activities between inferior and superior kernels,which mainly attributed to the significant decrease in SPSase,ADPGase and GS activities of inferior kernel. In conclusion,the increased plant density exacerbate the kernel position effect of summer maize,this was related to the lower grain-filling rate and kernel weight of inferior kernel since mid-grain filling stage,the lower grain filling rate in inferior kernel under dense planting was not only related to the insufficient post-silking dry matter accumulation,and it was also closely related to the lower activities of SPSase,ADPGase,and GS in inferior kernels.

In order to explore the effects of the combination of nitrogen application rate and nitrogen application period on the photosynthetic characteristics,senescence characteristics,grain filling characteristics and yield of leaves at ear position of summer maize under the integrated condition of drip irrigation,summer maize variety Zhengdan 958 was selected as the test material.Under the condition of 210 kg/ha,top dressing treatment at jointing stage,belling stage and flowering stage(A1),top dressing treatment at jointing stage and belling stage(A2),top dressing treatment at jointing stage and flowering stage(A3);under the condition of 180 kg/ha,top dressing treatment at jointing stage,belling stage and flowering stage(A4),top dressing treatment at jointing stage and belling stage(A5),top dressing treatment at jointing stage and flowering stage(A6);the traditional border irrigation was set as the control CK,and the total nitrogen application was 240 kg/ha,CK1 was topcoated with nitrogen fertilizer at jointing stage at one time,and CK2 was topcoated with nitrogen fertilizer at jointing stage and belling stage respectively,with a total of 8 treatments.The results showed that compared with CK1,A1 and A4 treatments not only maintained LAI and SPAD values in the late growth stage of summer maize,but also significantly increased the activity of antioxidant enzymes(SOD,POD and CAT),and effectively inhibited the content of peroxide MDA,so as to delay the aging process of its leaves and protect the functional structure of leaf cells.Therefore,the summer maize under this treatment maintained efficient photosynthetic characteristics in its later growth stage,promoted the grain filling rate,and then increased the number of grains per ear and 1 000 grains weight,so that the maize yield was significantly improved.The yield difference between A1 and A4 treatments was not significant difference,but the nitrogen application rate of A4 was reduced by 14.3% compared with A1,which reduced the input of nitrogen fertilizer and saved the input cost.It was the recommended treatment in this experiment.

In order to study the effects of straw returning on soil active organic carbon components and carbon cycle related enzyme activities in rice-rape rotation farmland of Chengdu Plain,we carried out 3-year straw returning field experiment(2017—2020),including no straw(CK),chemical fertilizer alone(NPK),50% straw returning and chemical fertilizer(SR1),100% straw returning and chemical fertilizer(SR2),200% straw returning and chemical fertilizer(SR3).We measured soil physical-chemical properties,soil organic carbon content(SOC),soil labile organic C fractions,carbon cycle related enzymes,and their correlations.The results showed that straw returning could effectively improve soil physical-chemical properties,soil available nitrogen,phosphorus and potassium contents.Compared with CK treatment,straw returning treatments significantly increased SOC,ROC,DOC,and MBC contents by 5.05%—8.55%,18.40%—36.80%,35.76%—66.93% and 27.20%—52.10%,respectively.In general,higher returning dosage resulted in higher C content.On the other side,compared with CK and NPK,straw returning treatments significantly increased soil cellulase,β-glucosidase,catalase,polyphenol oxidase.The activities of soil cellulase,β-glucosidase,and polyphenol oxidase under SR2 treatment were the highest,which were significantly higher than SR1 treatment by 16.25%,8.49%,and 14.69%,respectively.The catalase activity of SR3 treatment was the highest,which was significantly higher than that of SR1 treatment by 25.10%(P<0.05).There were significant positive linear correlations among soil SOC,labile SOC fractions,and carbon cycle related enzyme activities.Consequently,full straw returning has been proved of the most efficient way of improving active organic carbon components,carbon cycle related enzyme activities,and promoting the improvement of soil quality in rice-rape rotation farmland of Chengdu Plain.

Tillering stage and jointing—booting stage are important for the formation of panicle number and spikelets per panicle of rice,respectively.Nitrogen application affects the formation of panicle number and spikelet per panicle.Bacteria involve in soil nitrogen cycle.Two high-yield rice varieties,Y Liangyou 900 and Zaofengyou 69,were used to study the difference of soil bacterial number and community structure between tillering stage and jointing—booting stage,and the relationship between them and soil nitrogen,rice yield under two application ratios of nitrogen fertilizer(7:3 and 6:4 application ratios of basic tiller fertilizer to panicle-spikelet fertilizer).The results showed that there were significant differences in the structures of dominant bacterial groups in paddy soil between the tillering stage and jointing—booting stage,which were mainly Proteobacteria,Bacteroidetes,Chloroflexi and Acidobacteria.The relative abundance of Chloroflexi at the tillering stage was 6.16 percent points higher than that at the jointing—booting stage.The relative abundance of Acidobacteria at the tillering stage was 2.65 percent points higher than that at the jointing—booting stage.The relative abundance of Proteobacteria at the jointing—booting stage was 0.69 percent points higher than that at the tilling stage.The relative abundance of Bacteroidetes at the jointing—booting stage was 1.09 percent points higher than that at the tillering stage.The results of correlation analysis showed that rice yield was significantly negatively correlated with the number of soil bacteria at the tillering stage,but significantly positively correlated with the number of bacteria and total nitrogen content in the soil at the jointing—booting stage.There was a significant positive correlation between the number of effective panicles and the number of soil bacteria at the tillering stage.The number of spikelets per panicle was significantly positively correlated with the ammonia oxidation potential at the tillering stage and the jointing—booting stage.Redundancy analysis(RDA)showed that the bacterial community structures were affected by many factors.The contents of soil ammonium nitrogen and the ammonia oxidation potential were the main factors affecting the bacterial community structures at the tillering stage and the jointing—booting stage,respectively.The function prediction of FAPROTAX further indicated that the denitrification in the 7:3 treatment at the tillering stage was enhanced,especially in the soil of Y Liangyou 900.Therefore,increasing the number of soil bacteria at the tillering stage could enhance the number of effective panicles.Ammonia oxidation involved by soil bacteria at the jointing—booting stage can promote the increase of spikelets per panicle in rice.For the high-yielding rice varieties,Y Liangyou 900 and Zaofengyou 69 under different nitrogen application ratios,the formation of yield,effective panicle number and spikelets per panicle is closely related to soil bacterial number,community composition and ecological function.

In order to find out the regularities of formation of panicle grain characteristics of multi-panicle type and large-panicle type varieties to increase rice yield.The conventional field experiments method were conducted to use the multi-panicle type varieties Yueyou 9113(Y9113),the large-panicle type varieties Tianyouhuazhan(TYHZ)and Wufengyou T025(WT025)as test materials.To study the differences in carbon and nitrogen metabolism and yield composition of main stem,functional leaves and young panicles during the young panicle differentiation stages of multi-panicle type and large-panicle type varieties.The results showed that the activities of key enzymes in carbon and nitrogen metabolism(SPS,AMS,NR and GS)and soluble sugar and soluble protein content of the main stem,functional leaves and young panicles of large-panicle type varieties were higher or significantly higher than multi-panicle type varieties in the main young panicle differentiation stages.In the second branch and spikelet primordia differentiation stage,which the number of grains increased rapidly,the soluble protein content of functional leaves and soluble sugar content and GS activity of young panicles of Wufengyou T025 were significantly higher than Yueyou 9113 by 6.77%,35.07% and 20.10%,and the SPS activity of main stem and GS activity of young panicle of Tianyouhuazhan were significantly higher than Yueyou 9113 by 46.72% and 7.81%.In the meiotic stage of the pollen mother cell,which the spikelets are prone to degeneration and the number of grains decreases,the soluble protein content of functional leaves and soluble sugar content and soluble protein content of main stem of Wufengyou T025 were significantly higher than Yueyou 9113 by 9.88%,21.20% and 16.20%,and the soluble sugar content of main stem and SPS activity of functional leaves of Tianyouhuazhan were significantly higher than Yueyou 9113 by 14.67% and 28.55%.Under the conditions of this experiment,compared with the multi-panicle type varieties,the stronger carbon and nitrogen metabolism during the young panicle differentiation stage was one of the mechanisms of the large-panicle formation of the large-panicle type varieties.

The objectives of this study were to investigate the effects of nitrogen application rate on the grain yield,nitrogen accumulation and use efficiency of spring maize under different film mulching methods,and to provide a theoretical basis for efficient nitrogen application management of spring maize film mulching in high altitude area of Guizhou.Field trials were carried out from 2018 to 2019.The plots were arranged in a split-plot design.The main plots were assigned to the film mulching methods(wide film and narrow film) to be studied and divided into subplots according to the five nitrogen application levels(0,80,160,240 and 320 kg/ha).To study the effects of different film mulching methods and nitrogen application rates on yield,nitrogen accumulation,transport characteristics and utilization efficiency in different organs of spring maize.Film mulching,nitrogen application rate and their interaction significantly increased the yield of spring maize.The results showed that compared to narrow film mulching,wide film mulching not only increased the yield of spring maize by 17.8%,but also significantly enhanced the nitrogen accumulation and the retransfer of nitrogen accumulated before silking,then significantly increased the grain nitrogen accumulation.Moreover,compared to narrow film mulching,wide film mulching achieved significantly higher NUTE,NUPE,AEN,NPFP and NUE values showing increases of 4.9%,21.4%,23.5%,12.2% and 4.23 percentage points,respectively.Nitrogen application realized the synergistic growth of grain yield and plant nitrogen accumulation of spring maize,and could significantly affect nitrogen absorption,accumulation and transport.As the N application rate increased,the N translocation and the contribution rate of nitrogen transfer from vegetative parts to grain after silking could be effectively promoted,as well as enhanced.However,the nitrogen use efficiency,including the NDGPE,NHI,NUTE,NUPE,NUE,AEN,NPFP of spring maize,significantly decreased by increasing of N application rate.The regression analysis had shown that the optimal yield and nitrogen application rate for wide film mulching were reduced nitrogen application by 55 kg/ha and increased yield by 12.3% compared with narrow film mulching.The combination of wide film mulching and suitable nitrogen application rate was beneficial to the plant accumulation and absorption of nitrogen,so as to achieve high yield and nitrogen productivity,and then achieve the purpose of saving fertilizer and increasing yield.Considering the grain yield,N accumulation,transport and N use efficiency of spring maize,the reasonable N application rate of wide film mulching for spring maize in high altitude and other similar ecological zones in Guizhou was 160 kg/ha,which yield could reach 11 404.3 kg/ha.

To increase crop yields,reduce the application of chemical fertilizers,and improve nutrient utilization efficiency,N-efficient maize cultivars were screened and popularized. An understanding of nitrogen uptake,utilization,and field balance in maize cultivars with contrasting nitrogen efficiency response to N management is essential for efficient breeding and cultivation of maize to produce fodder and bio-energy. To determine the effects of N management on these factors during maize cultivation,a two-year field experiment was conducted in 2015 and 2016 in a subtropical semi-humid climate zone. The results showed that the proportion of N in the stem plus sheath and leaves in ZH311 during VT and R6 was significantly higher than that of XY508. In addition,the N accumulation into grain post-silking(NAG)and contribution of NAG to grain(CNAG)of ZH311 were significantly higher than those of XY508,while the N redistribution rate(NRR)and contribution of NRA to grain yield(CNRA)of ZH311 were significantly lower than those of XY508. The higher proportion of N in the vegetative organs of a N-efficient cultivar,ZH311,led to a significantly higher N accumulation in each stage than that observed for the N-inefficient cultivar XY508. The N accumulation advantage of ZH311 was higher after silking than before silking. The high post-silking N accumulation of ZH311 inhibited the pre-silking N transport that determines the N transport rate and contribution rate to grain of pre-silking N accumulation,which were significantly lower than those of XY508. Meanwhile,the N uptake efficiency,N recovery efficiency,and N partial productivity of ZH311 were significantly higher than those of XY508. Compared with that of XY508,the root system of ZH311 could more effectively absorb and utilize inorganic N in the 40-80 cm soil layer,reduce N deposition,and significantly decrease apparent N losses. The differences in apparent N losses between the two cultivars were mainly elicited post-topdressing. In summary,ZH311 has not only a higher yield per unit area than XY508,but also lower N losses,consequently reducing environmental risks.

To select the optimum tillage mode for the fluvo-aquic soil in North Henan,a three-year field experiment was carried out during 2016 to 2019. The experiment was designed with five combinations of three different tillage practices in wheat season as continuous rotary tillage(RT-RT-RT);deep tillage-rotary tillage-rotary tillage(DT-RT-RT);deep tillage-rotary tillage-strip rotary tillage(DT-RT-SRT);deep tillage-strip rotary tillage-strip rotary tillage(DT-SRT-SRT);deep tillage-strip tillage-rotary tillage(DT-SRT-RT). The photosynthetic indexes,soil available nutrients,and wheat yield were measured and analyzed under different treatments. The results showed that compared with RT-RT-RT,photosynthetic characteristics under different rotation tillage treatments improved. Compared with RT-RT-RT,the net photosynthetic rate,stomatal conductance under DT-SRT-RT increased by 10.85%,7.83%,respectively. The chlorophyll content increased gradually with the growth stage under DT-SRT-RT,and it was significantly higher than that under RT-RT-RT at the filling stage,with an increment of 16.52%. The content of available nitrogen,available phosphorus,and available potassium in the 0-50 cm soil layer increased under treatments with rotation tillage. Additionally,the spike number,grains per spike,1000-grain weight,and yield of wheat under DT-SRT-RT were higher than those under RT-RT-RT,therein,the yield under DT-SRT-RT was the highest with an increment of 14.64%. The correlation analysis showed that the net photosynthetic rate was positively correlated with wheat yield,which reached significant level at the flowering period. The contents of nitrate nitrogen,ammonium nitrogen,available phosphorus,and available potassium in surface soil were significantly positively correlated with wheat yield. Generally,for the fluvo-aquic soil area in North Henan,the photosynthetic characteristics of wheat,soil available nutrients content and the components of yield were improved by rotation tillage modes,and therein,the DT-SRT-RT was the optimum one.

In order to explore the control effect of nitrogen fertilizer on soybean cyst nematode disease,pot experiment and field experiment were carried out to analyze the effect of nitrogen fertilizer on the egg hatching,nematode development of soybean cyst nematode and the yield of soybean. Four nitrogen application levels were set as 0.016,0.032,0.048,0.064 g/kg soil,respectively,to analyze the effect of soil eluviating solution and root exudate solution on egg hatching. In the field experiment,four nitrogen application levels were set as 22.50,56.25,67.50,78.75 kg/ha,respectively,to analyze the effect of nitrogen fertilizer on the development of nematode. Treatment without nitrogen fertilizer was used as a blank control in all experiments. The results of pot experiment showed that both soil eluviating solution and root exudate solution could significantly improve egg hatching inhibition rate of H. glycines after nitrogen fertilizer application. The soil eluviating solution of 0.032,0.064 g/kg soil had the best inhibition effect on H. glycines egg hatching,reaching at 34.21% and 29.31%,respectively,the root exudate solution of 0.064 g/kg soil had the best inhibition effect on egg hatching of H. glycines,reaching 55.09%. The field experiment showed that proper application of nitrogen fertilizer could significantly decrease cyst number but increase soybean yield. Treatment with 56.25 kg/ha nitrogen fertilizer had the best control effect on nematodes and the highest yield of soybean,with cyst number decreased by 25.29% and the yield of soybean increased by 14.75%. However,the number of nematode in the control increased by 30.77%. Therefore,application of nitrogen fertilizer is an economical and safe control method to improve the yield and quality of soybean.

In order to select rotation crops suitable for tomato in southeastern of Shanxi Province,we planted six cropsrotation patterns,namely maize(LVZm),zucchini(LVCp),peanut(LVAh),green onion(LVAf),okra(LVAe),and cucumber(LVCs),taking treatment with continuous tomato cultivation(LLLe,CK)as control. The changes in the microbial community structure and diversity in the ITS1 region of soil fungi were analyzed by Illumina Miseq high-throughput sequencing technology. At the same time,the quality indicators(soluble total sugar,organic acid content,sugar-acid ratio,Vc content,soluble protein,soluble solids,lycopene content,nitrate)and yield indicators(single fruit weight,yield)of the following tomatoes were measured. The results showed that Ascomycote was the dominant phyla in the 7 treatments,and the species and abundance were quite different,LVCs,LVZm,LVAh and LVAe increased the diversity index of fungal,while LVCp decreased the index. LVZm had better taste;LVAe and LLLe had the highest Vc content;no significant difference in soluble protein content;the content of soluble solids were the highest in LLLe and LVCp;the content of lycopene was highest in LVCp;LVAe had the highest nitrate content. The yields significantly increased in LVAe and LVCp patterns,and the quality of single fruit significantly increased in LVCp rotation. Principal component analysis(PCA)showed that the scores of quality and yield among different patterns from high to low were LVCp>LVAe>LLLe> LVAh>LVAf> LVZm>LVCs. In summary,crop rotation changes the soil fungal community structure,affects the index of the fungal,the quality and yield of tomatoes in subsequent crops. Based on various factors,zucchini and okra are the dominant rotation crops suitable for the growth of local tomatoes.

This study investigated the dynamics of soil phosphorus,yield responses to soil phosphorus and phosphate fertilizer in winter wheat-summer maize rotation system in the last decades,which was important for the scientific application of phosphate fertilizer in continuous high-yielding cropping.A combined method that included in situ phosphate fertilizer experiment under different soil fertility conditions,the analysis of changes of soil available P since 1978,the response of yield to phosphate fertilizer was used.Average content of soil available P of winter wheat-summer maize rotation area was 22.43 mg/kg,and the soil available P of the piedmont plain of Taihang mountain was greater than the alluvial plain.During 1996-1999,the soil available P content of the the piedmont plain and the alluvial plain was 15.09,11.90 mg/kg in cultivated land,respectively,the application rate of P₂O₅ in the winter wheat season of the rotation system was 180 kg/ha;the soil P supply capacity for winter wheat in these two regions piedmont were 83.9%,75.8%,respectively,and for summer maize they were 83.3%,89.7%,respectively.Under the condition of winter wheat straw returning,soil P surplus of these two regions was estimated to be 52.8%,55.4%,respectively.During 2010-2012,the soil available P of the piedmont plain of Taihang mountain was 27.22 mg/kg,the application rate in winter wheat and summer maize season were 108,60 kg/ha,respectively.The soil P supply capacity in winter wheat season was 84.6%,90.1% in summer maize season.Soil P surplus was estimated to be 6.7% in winter wheat season,and soil P of deficit was estimated to be 47.1% in summer maize season without straw returning.The application rate of P₂O₅ for the maximal yield production of winter wheat and summer maize were calculated according to the yield responses of winter wheat and summer maize to the P fertilization rates at multiple sites during 2002-2006 and 2012-2016.For winter wheat they were 107.3,125.1 kg/ha,respectively,and for summer maize they were 52.0,58.9 kg/ha,respectively.The accumulated P increaded the yield of winter wheat and summer maize for excess application 3 time of P fertilizer in 3 years 6 crop.The recommendation of P₂O₅ rate for winter wheat and summer maize with wheat straw returning were 90-100 kg/ha and 30 kg/ha,respectively,and they were 100-120 kg/ha and 45 kg/ha without wheat straw returning.

Clarifying the regulation effect of nitrogen on grain development under heat stress at blister stage of maize is of great significance for rational fertilization,relieving the harm of heat and realizing high and stable yields.The effects of amount of nitrogen application(90,180,270 kg/ha,marked as N90,N180,N270)on the grain development and yield under heat stress during blister stage of maize were investigated by using Xianyu 335(XY335)and Zhengdan 958(ZD958)as materials and setting heat treatment(T)and control(CK).The results showed that heat stress broke the balance of endogenous hormones in maize grains, resulting in the decrease of abscisic acid (ABA) content in the grains of N180 and N270 of two maize varieties and auxin (IAA) content in the grains of N180 and N270 of ZD958; Soluble acid invertase activity (SAI) of upper grains was decreased, grain volume expansion and dry matter accumulation were blocked, abortion rate was increased, grain number per ear was decreased, and yield was significantly decreased. The heat-sensitive variety XY335 was more affected by heat stress than the heat-resistant variety ZD958.With the increase of nitrogen application rate,the negative effect of heat stress on corn grains development was intensified.Under heat stress,the ABA/GA₃ of XY335 and ZD958 decreased,the IAA and ZR contents increased,the grains volume and dry matter were more severely reduced,the abortion rate was significantly increased by 25.55,29.31 percentage points and 15.45,24.49 percentage points,respectively,the grains number per spike was decreased by 42.89%,52.68% and 20.95%,35.25%,respectively,and yield was significantly decreased by 44.29%,52.04% and 26.41%,39.94% respectively,under medium(N180)and high(N270)nitrogen treatments compared with low nitrogen(N90)treatment.Therefore,reasonable nitrogen application rate(N90)could alleviate the adverse effects of heat stress on corn grain development and reduce yield loss.