The aim was to elucidate the effects of different foliar fertilizer nitrogen application amounts on nitrogen accumulation,translocation,and utilization in maize.This experiment was conducted in 2021—2022 using a randomized block design,with maize variety Lihe 1 as the research object.No fertilization treatment (CK),conventional root fertilization treatment (CF),foliar nitrogen reduction treatment of 20% (LF1),foliar conventional nitrogen application treatment (LF2),and foliar nitrogen increase treatment of 20% (LF3) were set up to analyze the differences in nitrogen accumulation,translocation,and utilization of maize under different nitrogen fertilizer application amounts,no fertilization and conventional root fertilization.The results showed that the nitrogen accumulation in maize stems and leaves showed a trend of first increasing and then decreasing with the advancement of the growth stage,reaching the maximum value at the tasseling and silking stage.The nitrogen accumulation per plant gradually increased with the advancement of the growth stage and reached its maximum value at mature stage,the nitrogen accumulation per plant was highest in the LF2 treatment.The proportion of nitrogen distribution in leaves was highest before the silking stage;after the silking stage,the proportion of nitrogen distribution in grains gradually increased,reaching its peak at mature stage.The CK had the lowest proportion of nitrogen accumulation in grains,while the LF1 treatment had the highest proportion of nitrogen distribution in grains in 2021,and the LF3 treatment had the highest proportion of nitrogen distribution in grains in 2022.The nitrogen transport rate and the contribution rate of nitrogen transport to grains first increased and then decreased with the increase of nitrogen application amounts,the nitrogen harvest index and nitrogen utilization efficiency decreased with the increase of nitrogen application amounts;in 2021 and 2022,the nitrogen utilization efficiency of LF1 treatment,LF2 treatment,and LF3 treatment was higher than that of CF treatment,and the nitrogen utilization efficiency of LF1 treatment was the highest.The nitrogen absorption efficiency of foliar nitrogen application treatment for two years was higher than that of CF treatment.There were no significant differences in ear length,ear thickness,and ear row number among the treatments.CK had the longest bald tip length,and the row number and hundred grain weight of each nitrogen application treatment were higher than those of CK.CF treatment had the highest biological yield,while LF1 treatment had the highest grain yield and harvest index.The grain yield of each treatment was significantly higher than CK,and the harvest index decreased with increasing nitrogen application amounts.Therefore,maize can achieve better growth effects under LF1 foliar nitrogen application in the central and western regions of Inner Mongolia.

To explore the effects of nitrogen application rate on nitrogen uptake and translocation characteristics,nitrogen use efficiency,and the formation mechanisms of yield and quality in soft wheat under weak light stress during the after anthesis stage,under pot conditions,the soft wheat variety Quanmai 725(QM725)was used as the material,and the ¹⁵N tracer method was used.Two nitrogen rates were set in the experiment,namely N1(N 120 kg/ha),N2(N 180 kg/ha),and two shading treatments were set at the wheat filling stage(7-35 d after anthesis)under each nitrogen application rate,namely CK(no shading),SH(30% shading).The relationship between nitrogen application rate and grain yield and quality of soft wheat under weak light after anthesis was analyzed,and the effects of different nitrogen application rates on nitrogen accumulation,transport,grain yield and quality of soft wheat under weak light after anthesis were studied.The results showed that compared with the control,under the conditions of N1 and N2,the nitrogen accumulation of plants at flowering stage and vegetative organs at maturity stage was significantly reduced by weak light treatment after anthesis,and the proportion of nitrogen from fertiliser was significantly higher than that from soil nitrogen,while the proportion of nitrogen accumulation in grains at maturity stage from soil nitrogen was significantly higher than that from fertiliser nitrogen.Under the same nitrogen application rate,the proportion of basal nitrogen fertiliser was greater than that of topdressing nitrogen fertiliser.Under the same weak light treatment conditions,compared with N1,N2 increased the accumulation of fertiliser nitrogen at flowering stage,the accumulation of total nitrogen and fertiliser nitrogen at maturity stage,and the accumulation of total nitrogen,fertiliser nitrogen and soil nitrogen at maturity stage.Under N1 and N2 treatments,the nitrogen harvest index,nitrogen harvest index,nitrogen production efficiency,grain number per spike,1000-grain weight and grain yield of wheat decreased significantly with the decrease of light intensity after anthesis.The content and accumulation of protein and starch in soft wheat grains increased significantly with the increase of nitrogen fertilizer.However,under the same nitrogen application rate,weak light stress reduced the starch content,protein and starch accumulation in grains.Weak light stress after anthesis significantly affected the nitrogen accumulation of soft wheat plants,reduced the transport efficiency of storage substances from vegetative organs to grains after anthesis,resulting in a decrease in the contribution rate of vegetative organs to grains,which was not conducive to the overall nitrogen transport efficiency of plants.With the increase of nitrogen application rate,the nitrogen harvest index,nitrogen harvest index,nitrogen production efficiency and nitrogen use efficiency of wheat were significantly improved.Under the same nitrogen application rate of N1 and N2,after anthesis weak light stress significantly reduced the accumulation of protein and starch in soft wheat grains,which in turn affected the formation of grain weight,resulting in a decrease in yield.

To clarify the regulatory effect of nitrogen(N)fertilizer reduction and postponing on the productivity of wheat-maize double cropping system in Huang-Huai-Hai Plain.The annual N fertilizer experiment of summer maize and winter wheat was established of four N application systems:annual N fertilizer application 400 kg/ha of traditional farmer treatment(F₄₀₀),10% reduction of annual N fertilizer(FN),20% reduction of annual N fertilizer(FH),and 30% reduction of annual N fertilizer(FL)from 2020 to 2023 at Jiyang Experimental Base of the Shandong Academy of Agricultural Sciences in Jinan.The grain yield,aboveground N accumulation characteristics,N use efficiency,and the nitrate residue after harvest in the 0—200 cm soil layer of wheat-maize double cropping system were tested,in order to provide the theoretical basis for further optimization of N fertilizer management in Huang-Huai-Hai Plain.The results indicated that N fertilizer postponing was optimized the grain yield of summer maize and winter wheat under the condition of N reduction,and the averaged across the three years,FL significantly increased by 9.2%—18.1%,13.5%—20.5%,and 11.1%—19.1%,respectively,compared with F₄₀₀ and FN.N fertilizer postponing improved the N accumulation rate,and promoted aboveground N accumulation at wheat-maize different growth stages,and the averaged across the three years,FL significantly increased plant N accumulation by 5.7%—12.3% and 5.0%—12.8% under silking and maturity,respectively,compared with F₄₀₀,FN,and FH,as well as 8.2%—17.2% in grain N accumulation.For winter wheat,FL and FH treatments were significantly higher than F₄₀₀ and FN at jointing,anthesis,and maturity,and the averaged across the three years,FL and FH significantly increased by 23.4%—28.1%,20.7%—26.3%,and 12.6%—20.8%,respectively,compared with F₄₀₀,FN and FH,at the same time the grain N accumulation under FL significantly increased by 16.4%,15.0% and 5.8%,respectively,compared with F₄₀₀ and FN.N fertilizer postponing optimized the N use efficiency of wheat-maize double crop system,the averaged across the three years,FL significantly increased N uptake efficiency by 4.8%—57.7% and 32.0%—72.4% of summer maize and winter wheat,respectively,compared with F₄₀₀,FN,and FH;and FL significantly increased N partial factor productivity by 68.8% and 40.4% in summer maize,respectively,compared with F₄₀₀ and FN,as well as by 38.4%—71.8% in winter wheat compared with F₄₀₀,FN,and FH.At harvest of summer maize and winter wheat,the soil nitrate residue was mainly enrichment in the 0—40 cm soil layer under four N application systems,the averaged across the three years,accounted for 40.0%,38.9%,44.9%,42.5% and 37.3%,36.9%,46.7%,38.3% of the 0—200 cm soil layer,respectively.In addition,the obvious accumulated effects in 0—200 cm soil layer nitrate residue under F₄₀₀ and FN treatments at harvest of summer maize and winter wheat,but there was the relative balance was achieved under FL and FH treatments.In conclusion,a 30% reduction of annual N fertilizer by N fertilizer postponing could optimize plant N accumulation characteristics and realized synergistic improve grain yield and N use efficiency.Therefore,FL treatment was an optimal N application system for realizing the collaborative target of high-yield,high-efficiency,and environment-friendly of wheat-maize double cropping system in Huang-Huai-Hai Plain.

To clarify the effects of different nitrogen forms combined with magnesium fertilization on potato in the northern foothills of Yinshan Mountains,a field experiment was conducted in Hohhot,Inner Mongolia.The experiment included two nitrogen forms(nitrate nitrogen and ammonium nitrogen)and two magnesium application rates(0,45 kg/ha),resulting in four treatments.The impacts of these treatments on potato yield and its components,dry matter,nitrogen,magnesium,and potassium contents,their accumulation,and nitrogen use efficiency throughout the growth period were analyzed.The results showed that,compared with the application of nitrate nitrogen alone,the combined application of nitrate nitrogen and magnesium significantly increased potato leaf dry matter(21.24%—75.60%)and tuber dry matter(22.04%—62.36%)from tuber initiation stage to harvest stage,as well as whole-plant dry matter(32.54%—70.28%)from seedling stage to harvest stage.It also enhanced nitrogen accumulation(44.01%—69.84%)in tuber initiation stage,starch accumulation stage and harvest stage,whole-plant magnesium accumulation(37.66%—84.21%)during the entire growth period,whole-plant potassium accumulation (24.30%—54.95%) from tuber initiation stage to harvest stage, nitrogen uptake efficiency (30.77%—66.67%) during the entire growth period,and partial factor productivity of nitrogen fertilizer at harvest stage(35.13%).Correlation analysis indicated that potato dry matter,whole-plant nitrogen,magnesium,and potassium accumulation were significantly positively correlated with nitrogen uptake efficiency during the entire growth period(r was all greater than 0.78).At harvest stage,whole-plant potassium content showed a highly significant negative correlation with yield(r was -0.78).Principal component analysis further demonstrated that the total variation among treatments during the entire growth period was highly dispersed,indicating significant differences between nitrogen form combined with magnesium fertilization treatments and those without magnesium application.These findings provide a new strategy for improving nitrogen use efficiency and optimizing nitrogen-magnesium management in potato production in the northern foothills of Yinshan Mountains.

In order to study the physiological response and difference of nitrogen metabolizing enzyme activity in leaves of different forage oats in Horqin Sandy Land. The forage oats of Muwang and Tianyan No.1 were applied with 0 (CK), 100, 200, 300 kg/ha pure nitrogen in the proportion of 15%, 40%, 25% and 20% at tillering, jointing, heading and flowering stages. The activities of glutamate synthase (GOGAT), glutamine synthetase (GS), nitrate reductase (NR), glutamic oxaloacetic transaminase (GOT), glutamic pyruvate transaminase (GPT) were measured in flag leaf, inverted two leaf and converse third leaf during the filling period, and the differences of nitrogen metabolizing enzyme activities and their relationship with hay yield of different forage oat varieties under nitrogen application rate were analyzed. The results showed that the hay yield of Muwang and Tianyan No.1 reached the maximum at 200,300 kg/ha nitrogen levels, respectively;The activities of GOGAT, GS, NR, GOT and GPT in the leaves of Muwang and Tianyan No.1 forage oats increased first and then decreased with the increase of nitrogen application, and the enzyme activity was the strongest under N₂₀₀ nitrogen application (except for GOT activity of converse third leaf under N₃₀₀ treatment).Except for GS activity of the third leaf of N₁₀₀ treatment and GPT activity of the second leaf in different nitrogen treatments, GOGAT, NR, GS, GOT and GPT enzyme activities of Muwang were higher than those of Tianyan No.1. This indicated that nitrogen assimilation ability of forage oat variety Muwang was stronger than that of Tianyan No.1.Therefore, in Horqin Sandy Land, the suitable amount of topdressing nitrogen fertilizer for planting Muwang was 200 kg/ha, while for planting Tianyan No.1, topdressing nitrogen fertilizer of 300 kg/ha could obtain higher hay yield. GOT and GPT activities were the key enzymes for screening forage oat varieties with high nitrogen use efficiency.

To elucidate the regulatory effects of water-fertilizer coupling on fruit quality and taste substance accumulation in flavor tomatoes,greenhouse experiments were conducted using Yutianyou 6(premium flavor type)and 2442(common type)as test materials.Six water-fertilizer coupling treatments were established(W1F1:70%—75% ETc+180-90-150 kg/ha;W1F2:70%—75% ETc+240-120-200 kg/ha;W1F3:70%—75% ETc+300-150-250 kg/ha;W2F1:80%—85% ETc+180-90-150 kg/ha;W2F2:80%—85% ETc+240-120-200 kg/ha;W2F3:80%—85% ETc+300-150-250 kg/ha).The effects on yield,nutritional quality,sugar-acid components,and dynamic accumulation of soluble solids in greenhouse tomatoes were investigated.The results demonstrated that: both irrigation and fertilization exerted extremely significant effects on tomato yield.The W2 regime increased yields of Yutianyou 6 and 2442 by 22.3% and 19.6%,respectively,compared with W1.The highest yields were obtained under F3,reaching 33 720,33 480 kg/ha,respectively.Quality traits exhibited cultivar-specific responses.Vitamin C content was optimized in Yutianyou 6 under W1F2(0.383 mg/g)and in 2442 under W1F3(0.224 mg/g).Soluble protein accumulation was predominantly fertilizer-driven,peaking in Yutianyou 6 at W2F2(7.02 mg/g).Sugar-acid accumulation patterns varied between cultivars.Yutianyou 6 showed optimal glucose,citric acid,and malic acid accumulation under W2F2,with maximal fructose and sugar-acid ratio(8.326)achieved under W2F1.Conversely,2442 displayed weaker water responses,attaining its highest sugar-acid ratio(9.346)under W2F2.Soluble solids(Brix)displayed a rapid initial increase followed by stabilization,with W1F2 producing the optimal synergistic effect(peak 10.19% in Yutianyou 6)while conserving 12.5%—17.6% irrigation water and 20% fertilizer compared with W2F1.In conclusion,moderate water deficit combined with optimized fertilization can simultaneously enhance yield and quality.Yutianyou 6 is recommended for the high water-low fertilizer regime(W2F1),whereas 2442 is suited to the high water medium fertilizer regime(W2F2).

In order to explore the effects of different irrigation methods and nitrogen fertilizer management on late rice growth,development,yield formation,and nitrogen use efficiency,Y Liangyou 911 was used as test material.Two irrigation methods(W1.flooded irrigation;W2.moistening irrigation) and three nitrogen fertilizer managenments base,tiller,ear and grain fertilizer ratios(N1:5∶3∶2,N2:3∶4∶3 and N3:3∶4∶2∶1) were designed.No fertilization served as the control (CK1.flooded irrigation;CK2.moistening irrigation).Leaf area index,SPAD value of rice leaves,dry matter mass,yield formation and nitrogen use efficiency were determined under each treatment combination.The results showed that compared with W1,the LAI of rice treated with W2 was lower in the early growth stage and higher in the middle and late growth stages.The SPAD value of W1 treatment was higher,but there was no significant difference in SPAD value in the late growth period.Under the same irrigation conditions,compared with N1,N2 and N3 treatments it could delay the decline of LAI and SPAD values in the late growth period of rice.W2 treatment could significantly increase rice dry matter accumulation by 6.61%-16.37% compared with W1 treatment.Under nitrogen fertilizer treatment,the dry matter mass was higher in the early and middle stages of growth with N1,and the dry matter mass was higher in the later stages with N1 and N3.The yield increase of W2 mode was 7.59%-10.47% compared with W1 mode.The yield of W2N3 treatment was 3.24%-14.53% higher than that of other treatment.Although the effective panicle number was lower in W2N3 treatment,other yield components were increased,which resulted in higher yield.During the two years,W2N2 and W2N3 had higher values of total nitrogen accumulation and nitrogen absorption efficiency,W2N3 had higher values of nitrogen agronomic utilization,nitrogen partial productivity and nitrogen harvest index,and W1N3 had the higher value of physiological nitrogen utilization.In conclusion,irrigation methods and nitrogen management significantly affect rice yield and nitrogen uptake and utilization.The W2 (moistening irrigation) coupled with N3 (base fertilizer∶tillering fertilizer∶ear fertilizer∶grain fertilizer=3∶4∶2∶1) nitrogen management method is more conducive to rice dry matter accumulation,yield improvement and efficient use of nitrogen fertilizer,which can not only meet high yield,but also play a role in water saving.It is the best coupling method of water and fertilizer.

To investigate the effects of varying nitrogen(N)application rates on carbon and nitrogen metabolism and the formation of yield and quality in sugar beet,a field experiment was conducted at the Science and Technology Park of Inner Mongolia Agricultural University,Hohhot,Inner Mongolia Autonomous Region.Five N application treatments were implemented with rates of 0(N0),60(N60),120(N120),180(N180),240 kg/ha (N240).Dynamic changes in the main photosynthetic physiological indices,along with key enzymes and products involved in carbon and nitrogen metabolism of sugar beet,were analyzed under different treatments throughout its entire growth stage.The results showed that nitrogen application exerted significantly different effects on the photosynthetic characteristics,activities of key carbon and nitrogen metabolic enzymes and their metabolic products in sugar beet across different growth stages.In terms of photosynthetic characteristics,the SPAD values of all N-applied treatments on June 17 and July 2 were 10.06%—32.45%,4.19%—26.98% higher than those of N0,respectively.The N180 treatment showed the highest SPAD value and Fv/Fm on August 20,and exhibited relatively high SPAD values and Fv/Fm on September 20.Regarding the activities of key carbon and nitrogen metabolic enzymes,the N180 treatment exhibited the highest activities of sucrose phosphate synthase(SPS),sucrose synthase(SS),nitrate reductase(NR),and glutamine synthetase(GS)on July 17,which were 17.20%,20.37%,18.39%,31.30% higher than those of N0,respectively.In addition,the SPS activity on September 20 and SS activity on August 5 in the N180 treatment were also the highest,reaching 15.51,21.59 μg/(g·min),respectively.Regarding carbon and nitrogen metabolites,with the progression of the growth period,the soluble sugar content in taproots and the total nitrogen content in leaves both exhibited an overall increasing trend.The N180 treatment exhibited the highest total nitrogen content in both leaves and taproots on August 5,and the highest soluble sugar content in leaves on September 20.In terms of yield and quality,with the increase in nitrogen application rate,taproot yield showed an overall increasing trend,while sugar content exhibited an overall decreasing trend.Under the N180 treatment,the taproot yield reached 106.46 t/ha(31.00% higher than N0),the sugar content was 13.43%(0.63 percentage points lower than N0),and the sugar yield was the highest at 14.30 t/ha(25.11% higher than N0).Correlation analysis indicated that the activities of key enzymes(SPS,SS)of carbon metabolism were positively correlated with sugar yield,and carbon metabolites were negatively correlated with sugar yield overall.The activities of key enzymes(NR,GS)of nitrogen metabolism were positively correlated with sugar yield,and the total nitrogen content of taproots was positively correlated with sugar yield overall.In conclusion,a nitrogen application rate of 180 kg/ha optimized the photosynthetic performance of sugar beet leaves,promoted the coordination of carbon and nitrogen metabolism in leaves and taproots,balanced taproot yield and sugar content,and thus increased sugar yield.

Soil nitrogen(N)cycling enzyme activity serves as a crucial indicator for characterizing soil fertility and N transformation.To investigate the effects of long-term application of fertilizers on the soil enzyme activities correlated with N cycling in rhizosphere soil of double-cropping rice fields in southern China,our project was based on a continue 37-year fertilization localization field experiment,including four fertilization treatments:without fertilizer as a control(CK),single fertilizer(MF),rice straw residue and mineral fertilizer(RF),and 30% organic manure and 70% mineral fertilizer(OM).The activities of N cycling enzymes in the rhizosphere soil were measured,and their correlation with soil chemical properties was analyzed.The results were as follows:compared to MF and CK treatments,OM and RF treatments significantly increased the contents of total N(TN),organic carbon(SOC),ammonium N($\mathrm{NH}_{4}^{+}-\mathrm{N}$),nitrate N($\mathrm{NO}_{3}^{-}-\mathrm{N}$)and microbial biomass N(SMBN)in rhizosphere soil,and also increased rice yield.The urease(Ure)and nitrite reductase(NiR)activities of rhizosphere soil in OM and RF treatments were significantly higher than those in MF and CK treatments.The RF treatment significantly increased rhizosphere soil hydroxylamine reductase(HyR)activities compared to the other three treatments,by 21.7%,13.0%,and 8.7%,respectively.This finding shown that OM treatment significantly increased protease(Pro),nitrogenase(Nit),nitrate reductase(NR)and nitrous oxide reductase(Nos)in rhizosphere soil compared to RF,MF and CK treatments.In comparison to MF treatment,OM treatments increased Pro,Nit,NR and Nos activities in rhizosphere soil by 20.0%,26.1%,426.1% and 26.7%,respectively.Nonetheless,the activity of nitric oxide reductase(Nor)on rhizosphere soil was considerably higher in the CK treatment than in MF,RF and OM treatments.Pearson correlation analysis revealed a substantial positive correlation between soil NR,NiR,Nit,Nos,Ure,Pro and soil TN,SOC,$\mathrm{NH}_{4}^{+}-\mathrm{N}$,$\mathrm{NO}_{3}^{-}-\mathrm{N}$,SMBN as well as rice yield.Soil Nor activity was observed to have a significantly negative connection with soil TN,SOC,$\mathrm{NH}_{4}^{+}-\mathrm{N}$,$\mathrm{NO}_{3}^{-}-\mathrm{N}$,SMBN and rice yield.The findings presented above showed that soil chemical properties and yield were substantially related to rhizosphere soil N cycling enzyme activities.Redundancy analysis(RDA)showed that the first order axis could explain 93.34% of the enzyme activity in rhizosphere soil and soil $\mathrm{NO}_{3}^{-}-\mathrm{N}$,TN and SOC contents were the key factors affecting the pattern of rhizosphere soil enzyme activities.Therefore,the long-term application of organic materials such as organic manure and rice straw can enhance soil chemical and biological characteristics,stimulate soil N cycling enzyme activities,and effectively fertilize paddy soils by partially replacing chemical fertilizers.

To clear under the condition of slow release nitrogen fertilizer applying different content of maize development rule of the diurnal change of photosynthetic characteristics and growth,the light response curve was to fit,so as to farming-pastoral zone of spring maize cultivation and nitrogen utilization to provide theoretical basis.This study took Guangde 5 as the research object,and based on the long-term positioning experiment in 2018,the leaves ear position in spinning—tasseling stage of maize were mesured and analyzed under six nitrogen gradient of N 0(N0,CK), 120(N8), 180(N12), 240(N16), 300(N20),360(N24) kg/ha in 2019 and 2020. SPAD value, intercellular carbon dioxide concentration, stomatal conductivity, diurnal variation of net photosynthetic rate, transpiration rate, light response curve and dry matter accumulation rule.The results showed that with the increase of nitrogen fertilizer application, the changes of SPAD value, net photosynthetic rate, transpiration rate and stomatal conduction degree day of maize increased first and then decreased,and N16 treatment was the highest,and intercellular carbon dioxide concentration was the lowest.The changes of net photosynthetic rate,transpiration rate and stomatal conduction degree day showed unimodal curve.The light response curve fitting analysis showed that the maximum net photosynthetic rate of N16 treatment was the highest.In 2019 and 2020,N16 treatments were 37.48%,29.51%,31.85%,18.17%,37.32% and 80.04%,59.73%,50.30%,6.42%,62.51% higher than N0,N8,N12,N20 and N24 treatments,respectively.Dry matter mass accumulation in whole plant and ear were positively correlated with maximum net photosynthetic rate,apparent quantum efficiency and SPAD value.Comprehensive analysis showed that the most suitable nitrogen fertilizer application rate in western Inner Mongolia was 240 kg/ha.

To improve the applicability of biochar in saline-alkali agroecosystem,the effect and microbial mechanism of modified biochar were studied.In a 2-year field experiment,common biochar(4.5 t/ha),nitrogen-rich modified biochar(7.5 t/ha)and phosphorus-rich modified biochar(15.0 t/ha)were added to investigate their impact on crop grain yield,soil physicochemical properties and soil microbial diversity.It had been observed that the addition of biochar enhanced the quality of saline-alkali soil,with nitrogen-rich modified biochar and phosphorus-rich modified biochar demonstrating more notable effects.Biochar could boost crop yield,improve soil structure and reduce soil bulk density in saline-alkali land.The effects of the three biochar types were not consistent.Among them,the application of 15.0 t/ha phosphorus-rich modified biochar showed favorable responses,with grain yield of(8.92±0.12)t/ha,representing a 110% increase compared to the control group.Biochar affected soil microbial diversity.Common biochar increased soil microbial diversity,whereas phosphorus-rich modified biochar decreased it.With the continuous addition of biochar,soil physical and chemical properties could affect the relationship between soil microorganisms and plant structure,weakening their relationships.In this study,the application of 15.0 t/ha phosphorus-rich modified biochar was recommended to improve saline-alkali agroecosystem.

To investigate the responses of different types of wheat to various nitrogen-phosphorus-potassium ratio compound fertilizers in the Huaihe River region,in terms of photosynthetic characteristics,dry matter accumulation and distribution,yield and quality,four wheat varieties(Zhongke 166,Yannong 999,Huaimai 43,Shannong 17)were selected as experimental materials.Two types of compound fertilizers were set up:high-nitrogen compound fertilizer(N-P₂O₅-K₂O=26-13-7)and equal-proportion compound fertilizer(N-P₂O₅-K₂O=18-18-18).The effects of different compound fertilizer treatments on the photosynthetic characteristics,dry matter accumulation and distribution,yield and quality of each wheat variety were analyzed.The results showed that compared with the equal-proportion compound fertilizer,the high-nitrogen compound fertilizer significantly increased the LAI,SPAD value,net photosynthetic rate and photochemical efficiency of the four varieties,delayed leaf senescence,and prolonged photosynthetic time;it also increased the dry matter accumulation at the flowering and maturity stages,optimized the dry matter distribution ratio,and ultimately increased the grain yield by 4.5% to 14.9%,with protein and wet gluten contents increasing by 1.36% to 8.17% and 3.55% to 9.36% respectively.The response of different varieties to the high-nitrogen compound fertilizer varied slightly,with Yannong 999 having the best overall performance,the largest increase in SPAD value and LAI,the highest net photosynthetic rate and yield,the highest dry matter distribution ratio at the maturity stage,and significant quality improvement;Zhongke 166 had the largest yield increase,the highest protein content and wet gluten content;Huaimai 43 had the highest increase in grain dry matter accumulation;Shannong 17 had the weakest response to the high-nitrogen compound fertilizer,but its yield was still 9.3% higher than that of the equal-proportion compound fertilizer.In summary,the high-nitrogen compound fertilizer showed significant advantages in the photosynthetic characteristics,dry matter accumulation and distribution,yield and quality of different types of wheat.Among them,Yannong 999 had the best overall performance.

The aim was to clarify the effects of different nitrogen application levels on soil organic nitrogen fractions and nitrogen use efficiency in maize fields in the central-western region of Inner Mongolia,so as to provide a reference for the scientific management of soil nitrogen and sustainable development of modern agriculture.Six nitrogen application levels were set up,N0(0 kg/ha),N8(120 kg/ha),N12(180 kg/ha),N16(240 kg/ha),N20(300 kg/ha),and N24(360 kg/ha).The dynamic changes with effects of nitrogen application on soil total nitrogen content,particulate organic nitrogen content,light fraction organic nitrogen content and heavy organic nitrogen content,as well as maize yield and nitrogen use efficiency were analyzed at different soil layers at pre-sowing and post-harvest.The results showed that soil total nitrogen,particulate organic nitrogen,light fraction organic nitrogen,and heavy fraction organic nitrogen content decreased with deepening of the soil layer at the same nitrogen application level;soil total nitrogen content at pre-sowing increased with the nitrogen application levels.Soil total nitrogen content in the N16,N20,and N24 treatments was significantly higher than that in the N0,N8,and N12 treatments at post-harvest.Soil particulate organic nitrogen content of N16 treatment was highest in the 0—10 cm,10—20 cm,and 20—40 cm soil layers at pre-sowing,with 0.14,0.13,and 0.09 g/kg,respectively.At post-harvest,N16 treatment had the highest content in the 10—20 cm,20—40 cm,and 40—60 cm soil layers,with 0.19,0.10,and 0.09 g/kg,respectively.The highest increase of soil light fraction organic nitrogen content of 37.27% was in the N16 treatment,and the highest increase of soil heavy fraction organic nitrogen content of 7.35% was in the N24 treatment,followed by the N16 treatment,at 6.84%.The N16 treatment had the highest maize biological yield of 31 443.50 kg/ha;the highest maize economic yield of 18 526.47 kg/ha;and the nitrogen use efficiency decreased with the increase in nitrogen fertilizer application levels,N16 treatment in the nitrogen harvest index was the highest, at 79.20%.In conclusion,the more suitable nitrogen fertilizer application level in the central-western region of Inner Mongolia should be maintained under 240 kg/ha,in order to achieve the best soil nitrogen management ang crop yield.

In order to explore the effect of straw interlayer on soil respiration and the chemical structural stability of organic carbon components during the remediation of saline-alkali soil,two experimental treatments were set up in the alfalfa-planting farmland at the Saline-Alkali Soil Improvement Experimental Demonstration Base in the Agricultural High-Tech Zone of Dongying City,Shandong Province:a straw interlayer treatment (S,with a 5 cm thick straw layer buried at a 35 cm depth) and a control (CK,without an interlayer). Soil respiration characteristics of the different treatments were analyzed,and comprehensive discussions were conducted in conjunction with soil pH,electrical conductivity(EC),organic carbon component content,and chemical structure characteristics of the soil profile.The results showed that:compared with CK,the S treatment significantly increased the soil respiration rate during the alfalfa growth period, with a maximum increase of 79.84%. Furthermore, the S treatment reduced soil EC in the straw interlayer (35—40 cm) and the overlying soil layer (0—35 cm), effectively inhibiting the upward migration of salt. The 40—50 cm soil layer was identified as a critical zone for organic carbon transformation. In this layer, the S treatment significantly increased SOC content (by 16.67%) and highly significantly elevated particulate organic carbon (POC) and dissolved organic carbon (DOC) contents (by 208.07% and 83.41%, respectively) compared with CK. Characterization of the molecular structure of organic carbon in the 40—50 cm layer revealed distinct responses. For DOC, the S treatment reduced the magnitude-weighted averages of unsaturation (by 30.60%) and aromaticity index (by 4.84%) compared with CK, decreasing the proportion of unstable carbon. For POC, the S treatment increased the relative abundances of alkyl C(10.32 percentage points)and O-alkyl C (8.39 percentage points) while reducing carboxyl C (14.24 percentage points), thereby enhancing POC structural stability. However, for bulk SOC, the S treatment decreased the proportions of alkyl C(3.14 percentage points) and aromatic C(3.38 percentage points) while increasing O-alkyl C(5.17 percentage points)and carboxyl C(1.56 percentage points). This shift indicated a decrease in recalcitrant carbon and an increase in labile carbon, resulting in reduced SOC structural stability. Correlation analysis showed that the significant increased in soil respiration was highly significantly and significantly positively correlated with POC and SOC contents in the critical soil layer, respectively. Specifically, the accumulation of O-alkyl C(a labile component) in the chemical structure of SOC reduced the stability of organic carbon,which was the main reason for the increase in soil respiration.In conclusion,incorporating a straw interlayer significantly increased soil respiration in the short term,which was closely related to the reduction in the stability of the organic carbon chemical structure in the key soil layer.Under future "carbon neutrality" strategies,research on the selection of interlayer materials should be considered.

To explore the relationship between soil bacterial community diversity and soil enzyme activity of Qinqiong(Q) and Magnum(M) under salinity stress treatment,the bacterial community structure and soil enzyme activity of Qinqiong and Magnum for 0,6,12,24,48 h were compared and analyzed by using high-throughput sequencing of bacterial 16S rRNA and colorimetry.The results indicated that at the phylum level,the relative abundances of Actinobacteria and Proteobacteria in the rhizosphere soil of Qinqiong were higher than those in Magnum.At the genus level,the relative abundances of Bacillus and Arthrobacter in the rhizosphere soil of Qinqiong were greater than those in Magnum,while the relative abundance of Pseudomonas was lower compared to Magnum.After 48 hours of saline-alkali stress,the activities of soil polyphenol oxidase(S-PPO),soil catalase(S-CAT),soil dehydrogenase(S-DHA),and soil invertase(S-AI) in the rhizosphere of Qinqiong were 1.32,1.53,1.38,and 1.28 times higher than those of Magnum,respectively.Furthermore,the S-CAT activity exhibited a significant positive correlation with the bacterial ACE and Chao diversity indices.Qinqiong may influence changes in bacterial community structure by altering the relative abundances of dominant bacterial groups,thereby enhancing the bacterial community diversity index and soil enzyme activity.In contrast,the changes in the bacterial community within the rhizosphere of Magnum were not significant.The diversity of soil microbial communities is a critical factor determining the saline-alkali tolerance of oat varieties.

In order to clarify the change rule of photosynthetic characteristics and the best fertilization method in different growth stages of sweet sorghum under different fertilization treatments, the field experiment was conducted to study the stomatal conductance (Gs), intercellular CO₂ concentration (Ci), transpiration rate (Tr), net photosynthetic rate (Pn), chlorophyll (SPAD), water use efficiency (WUE) and yield of New Sorghum No.3 under 8 different fertilization treatments, including CK, NK, NP, PK, NPK, M (organic fertilizer), NPKM and 1.5NPKM.The results showed that the changes of Pn, Gs, WUE and SPAD value in sorghum leaves under different fertilization treatments were the same at different growth stages, showing a trend of first increasing and then decreasing, and peaking at grain filling stage. The variation trend of Tr and Ci from flowering stage to maturity stage decreased first and then increased, and reached the lowest value in grain filling stage. At the same growth stage, the photosynthetic characteristics of different fertilization treatments were different, and the photosynthetic characteristics of leaves were affected by fertilization treatments. The Tr, Gs and Ci values of NPKM fertilization treatment at maturity stage were higher than those of other treatments, which were 3.64 mmol/(m²·s),328 mmol/(m²·s),439 μmol/mol, respectively. The correlation analysis showed that Pn of NPKM treatment at flowering stage was significant positively correlated with Tr and WUE, while Pn of NPK treatment was positively correlated with Gs and Ci. The biological yield of all fertilization treatments was significantly higher than CK, among them the biological yield of NPKM treatment reached 94.81 t/ha. The biological yield of NPKM increased 97.95%, 26.65%, 20.24%, 19.57%, 15.16%,14.98% and 11.74% respectively compared with CK, M, 1.5 NPKM, NK, PK, NPK and NP. Fertilization affects the photosynthetic parameters of the leaves of New Sorghum No.3 and was conducive to increasing yield. Therefore, it is feasible to use high photosynthetic efficiency breeding to improve biological yield. In order to alleviate the obstacle of continuous cropping of sweet sorghum, different proportion of fertilizer should be adopted. In a word, NPKM is the best fertilization mode to improve photosynthetic conditions and maximize yield, so it is preliminarily confirmed that NPKM is the best fertilization mode to promote the growth and development of continuous cropping sorghum in arid area.

Clarify the effect of straw returning and nitrogen fertilizer reduction on chlorophyll content,dry matter accumulation and yield of mung beans in Inner Mongolia central region,and to provide reference for the rational utilization of straw resources and scientific nitrogen application in mung bean cultivation.It used Kelyu 1 mung bean as the material and two factor split zone design was used.Two cultivation measures were set up:straw returning(ST)and no straw returning(NST)and four nitrogen fertilizer application levels were set up:0(N0),45(N45),90(N90),135(N135)kg/ha,for a total of eight treatments.To analyze the effects of different treatments at different stages on mung bean on chlorophyll content,dry matter weight of aboveground organs,main agronomic traits at maturity stage,yield and its components.The results showed that the chlorophyll content,dry matter weight of aboveground organs,main agronomic traits,yield and its constituent factors of mung beans treated differently at different stages were as follows:ST+N90>ST+N135>ST+N45>NST+N90>NST+N135>NST+N45>ST+N0>NST+N0.Compared with the NST+N0 treatment,ST+N90 treatment had the highest chlorophyll content at the podding stage,leaf dry matter weight at the flowering stage,stem dry matter weight at the maturity stage,pod dry matter weight at the podding stage,grain dry matter weight at the maturity stage,number of main stem branches,number of main stem nodes,pod length,pod width,number of pods per plant,number of seeds per pod,100-seed weight,and yield of mung beans,with increases of 24.33%,30.56%,26.83%,28.58%,43.85%,6.13%,7.03%,5.62%,16.35%,13.22%,4.45%,8.90% and 23.46%.The straw returning with 90 kg/ha nitrogen fertilizer application treatment can increase the mung beans chlorophyll content,promote the accumulation of aboveground organs dry matter weight,and improve the yield.It is an ideal measure in mung bean cultivation.

In order to explore the effects of mulching measures(such as straw returning and plastic film mulching)on soil aggregates and organic carbon in semi-arid rain-fed agricultural areas.The potato-wheat rotation system in the dryland of Longzhong was used as the research object.The effects of straw stubble mulching(SR),straw strip mulching(SM),plastic film mulching(PM)and open field(CK)on soil organic carbon components(SOC,POC,MAOC),aggregate stability and aggregate carbon contribution rate were systematically analyzed.By evaluating the soil improvement effect of different mulching measures,integrating the intrinsic indicators such as soil organic carbon component dynamics,aggregate stability and crop productivity and water use efficiency data reported in the literature,the optimal mulching mode that can synergistically improve organic carbon and aggregate stability was screened.The results showed that the organic carbon content and aggregate stability of potato and wheat were improved by three mulching measures in potato-wheat rotation,and the effect of SR treatment was the best.Compared with CK treatment,the SOC content of SR and SM treatment increased by 15.38% and 7.78%,and the SOC content of PM treatment did not change significantly.SR and SM treatment increased the POC content in 0—20 cm soil layer by 18.54%,16.62%,and PM decreased the POC content in 0—20 cm soil layer by 3.06%.The overall trend of MAOC increased in each treatment was SR>SM>PM>CK.Compared with CK treatment,SR and SM treatments increased the proportion of MWD,GMD,>2 mm aggregates and SOC content,while PM significantly reduced MWD and GMD.SR increased the SOC enrichment coefficient of>2 mm aggregates by 17.26% in 0—20 cm soil layer,and SR and SM treatments significantly increased the SOC contribution rate of>2 mm aggregates.In summary,under the conditions of this experiment,all three mulching measures can increase soil organic carbon content,and straw stubble mulching returning to the field has the best effect in improving soil organic carbon content and aggregate stability,effectively improving soil fertility.

In order to provide production advice of high-quality upper tobacco leaves,field experiment was carried out to elucidate the effects of nitrogen application on the growth,development,carbon and nitrogen metabolism of upper leaves of different tobacco varieties.Three treatments,37.5(LN),75.0(MN)and 112.5 kg/ha nitrogen application rate(HN)were conducted with NC89 and Yunyan 87 as the test varieties.The effects of different treatments on the agronomic traits,photosynthetic characteristics,leaf tissue structure,key enzymes activity of carbon and nitrogen metabolism,and chemical composition of the upper leaves of were studied.The results showed that the leaf length,leaf width,leaf area,and leaf dry mass of the upper leaves of both varieties were significantly improved with the increased of nitrogen application rates.At 115 days after transplanting(DAT),the leaf area of NC89 and Yunyan 87 of HN were significantly increased by 63.10% and 68.43% compared to LN,respectively.Increasing nitrogen rate improved the leaf chlorophyll content of NC89,the leaf chlorophyll content of HN was 6.67%—37.50% higher than that of LN,respectively.The leaf net photosynthetic rate was notably improved by increasing nitrogen rate of Yunyan 87,especially at 70 DAT and 80 DAT.The leaf palisade tissue,leaf spongy tissue,and leaf thickness were markedly promoted with the increased nitrogen application rate on 85—115 DAT.The palisade tissue and spongy tissue thickness of LN and MN were almost stable from 95 to 115 DAT,but HN improved by 9.82%—14.08% and 10.72%—13.72% respectively.The leaf carbon content and leaf carbon and nitrogen ratio of both varieties were significantly decreased by reduced nitrogen rate,while leaf nitrogen content significantly increased.The activities of invertase,sucrose phosphate synthase,sucrose synthase,and glutamate synthase of both varieties were increased with the increased nitrogen application rate.HN decreased the amylase activity of Yunyan 87,but increased that of NC89.At 115 DAT,the amylase activity of HN of Yunyan 87 was 27.53% lower than MN,while HN increased amylase activity by 33.86% and 21.74% compared to LN and MN of NC89,respectively.The activity of glutamine synthetase of Yunyan 87 significantly increased with the increased nitrogen application rate,while there was no significant difference among different treatments of NC89.The content of flue-cured tobacco leaf reducing sugar and total sugar were reduced,but the content of nicotine and total nitrogen were improved with increased nitrogen application rate.Under the same nitrogen application rate,the content of flue-cured tobacco leaf nicotine,total nitrogen,and potassium of Yunyan 87 were higher than NC89,while the content of reducing sugar,content of total sugar(except LN),sugar and nicotine ratio,and nitrogen and nicotine ratio were lower than NC89.The effect of nitrogen application rate on upper leaves of tobacco varieties is difference.Increasing nitrogen application rate could promote the growth,development and carbon metabolism,reduce sugar and nicotine ratio and nitrogen and nicotine ratio,and improve the coordination of chemical components of NC89.However,increasing nitrogen application rate could lead to excessive nitrogen metabolism,delay the transformation from nitrogen metabolism to carbon accumulation metabolism,and cause late maturity of Yunyan 87.

In order to clarify the effects of climate change and organic fertilization on soil nitrogen cycling,a soybean field experiment was conducted in Hefei, Anhui from June to November 2023. Field warming was simulated using infrared radiation warming equipment, and two temperature levels(T0:Ambient temperature;T1:Warming)and different fertilization managements(SF:Synthetic fertilization;OF:Organic fertilization),and determined the effects of warming and organic fertilization on nitrification and denitrification processes and their drivers by investigating soil physicochemical properties,the relative contributions of ammonia-oxidizing bacteria(AOB)and archaea(AOA)to the nitrification potential,denitrification capacity and N₂O/(N₂O+N₂)ratio,as well as soil respiration in combination with enzyme activity measurements.The results showed that warming significantly decreased soil moisture(2.3 precentage points),organic carbon(22.7%),total phosphorus(23.8%),N${\mathrm{H}}_{4}^{+}$-N(17.5%),while significantly increased NO₃^--N(52.8%);organic fertilization significantly increased soil moisture,organic carbon,total phosphorus,NH₄⁺-N content by 1.2 percentage points,26.5%,31.3%,17.0%,respectively.Warming increased soil respiration(26.4%),nitrification potential(31.7%),AOB contribution(16.4 percentage points),denitrification capacity(49.1%),N₂O/(N₂O+N₂)ratio(10.5 percentage points).Organic fertilization significantly decreased the nitrification potential, AOA contribution, denitrification capacity, and N₂O/(N₂O+N₂)ratio by 39.3%, 18.2 percentage points, 24.7% and 16.2 percentage points,respectively.Warming and organic fertilization significantly increased urease (S-UE), nitrite reductase (S-NiR), and hydroxylamine reductase(HR)activities.The correlation analyses showed that NO₃^--N content,S-UE,S-NiR,and HR activities were significantly positively correlated with AOB contribution rate and denitrification capacity.Therefore,warming increased soil N${\mathrm{O}}_{3}^{-}$-N content and the activities of S-UE,S-NiR and HR,which in turn increased the nitrification contribution of AOB,denitrification capacity and N₂O/(N₂O+N₂)ratio,leading to an increase in the loss of N₂O;while organic fertilization could increase the soil nutrients and regulate the role of AOA and AOB in the nitrification process,reduce the contribution of AOA,denitrification capacity and N₂O/(N₂O+N₂)ratio,and thus decrease the N₂O loss,consequently,mitigating the adverse effects of warming.

To investigate the effects of long-term fertilization on yield formation and its physiological regulation mechanisms in double cropping late rice,it utilized a long-term fertilization experiment(initiated in 1981)in red paddy soils of Jinxian.Four typical treatments were selected:no fertilization(CK),single application of nitrogen-phosphorus-potassium(NPK),double dose of NPK(HNPK),and combined organic-inorganic fertilization(NPKM).Comparisons were made on double cropping late rice yield,dry matter accumulation,chlorophyll dynamics,and differential gene expression in leaves at fullheading and filling stages in the 42nd year of long-term fertilization.Results showed that long-term fertilization resulted in yields ranked as NPKM>HNPK>NPK>CK,with HNPK and NPKM treatments significantly surpassing NPK,showing increases of 29.63% and 57.18% respectively.Compared with NPK,both NPKM and HNPK significantly improved yield components:effective panicles,grains per panicle,and grain density increased by 16.98%—46.42%,8.68%—15.26%,3.69%—7.37%,respectively.Regarding dry matter accumulation,NPKM and HNPK significantly enhanced dry matter weight at all growth stages and promoted translocation of stem-leaf dry matter to panicles from filling to maturity.The contents of chlorophyll in NPKM and HNPK treatments were significantly higher than those in CK and NPK treatments at all stages,and NPKM delayed the decay of chlorophyll from filling stage to maturity stage.Correlation analysis revealed significant positive relationships between yield and dry matter accumulation from tillering to heading(△DM1)and filling to maturity(△DM3),while showed extremely negative correlation with chlorophyll reduction from grain filling to maturity(△S3).Transcriptome analysis demonstrated that long-term fertilization significantly affected gene expression in leaves during fullheading and filling stages,with differentially expressed genes primarily enriched in photosynthesis,carbon/nitrogen metabolism,signal transduction,and stress-related pathways.In conclusion,long-term fertilization regulates gene expression and combined organic-inorganic fertilization improved yield components,enhanced early-stage dry matter accumulation,promoted assimilate translocation from vegetative organs to panicles during grain filling,maintain higher chlorophyll levels,and delayed leaf senescence post-grain filling.This comprehensive mechanism achieves yield enhancement through strengthening source(enhancing photosynthetic capacity),expanding sink(increasing dry matter storage),and facilitating flow(promoting assimilate transport).

In order to study the effects of different nitrogen application rates on rice yield,nitrogen uptake and soil fertility,the effects of different nitrogen application levels on rice yield,nitrogen use efficiency and soil tillage fertility in the Yellow River Irrigation Area were studied from 2021 to 2023 using rice variety Fuyuan 4 as the test material.Compared with other treatments,the average yield of 360 kg/ha was 9.4 t/ha,which was 182.94% higher than that of no nitrogen treatment,and 40.72% and 26.34% higher than that of 210,240 kg/ha.From the perspective of yield components,the increase in yield was mainly due to the increase of grain number per spike and the number of effective spikes,and excessive nitrogen application would cause the decrease of 1000-grain weight.The average of the 3-year results showed that the nitrogen use efficiency was up to 26.93% with 240 kg/ha of nitrogen,and the partial productivity of nitrogen fertilizer decreased with the increase of nitrogen application rate.The highest average value of organic matter was 18.60 g/kg after nitrogen application of 210 kg/ha.Compared with the non-nitrogen application treatment,the soil total nitrogen content of each nitrogen application treatment increased by 7.61%—15.67%,and the soil total nitrogen content of the 360 kg/ha nitrogen application treatment decreased with the increase of the experimental year.The total phosphorus content of soil was gradually reduced in the 360 kg/ha nitrogen application treatment,and the total phosphorus content in other nitrogen application treatments was maintained at about 0.85 g/kg.The total potassium content of nitrogen fertilization treatments gradually decreased with the increase of nitrogen application rate,and the total potassium content of the 360 kg/ha nitrogen application treatment decreased by 23.74%,22.16% and 8.85%,respectively,compared with the nitrogen fertilization treatments of 120,210 and 240 kg/ha.Soil available phosphorus increased with the years of the experiment,and the variation range between treatments increased with time.With the increase of nitrogen application rate,soil available phosphorus increased first and then decreased,and the soil available phosphorus of the 240 kg/ha treatment increased significantly in 2023 compared with other treatments.The soil available potassium of each treatment did not change significantly with the test years.By considering crop yield,nitrogen use efficiency and soil fertility,nitrogen application of 240 kg/ha could balance the environment and production requirements.

Soil salinization is an important constraint on the improvement of farmland productivity.In view of the poor quality and low productivity of coastal salinized soil,a pot experiment was set up to explore the effects of different dosages and ratios of organic soil conditioners on the growth and soil properties of soybean in coastal salinized farmland.The results showed that the comprehensive analysis of the physiological indicators of salt resistance,such as SOD,CAT,and MDA,showed that T3(lactose peptide 225 kg/ha,lactose peptide:inositol=10:1)and T5(lactose peptide 225 kg/ha,lactose peptide:inositol=20:1)had good improvement effects.Comparing the growth trend in the early and medium stages,T5 treatment showed good growth status,followed by T2(lactose peptide dosage 225 kg/ha,lactose peptide:inositol=5:1).In terms of dry matter accumulation and nutrient uptake,T16(lactose peptide dosage 900 kg/ha,lactose peptide:inositol=15:1),T17(lactose peptide dosage 900 kg/ha,lactose peptide:inositol=20:1)and T2 were better than those of the control treatment.The partial productivity and agronomic efficiency were the highest in T2,which were 1.11,0.87 g/kg,and the compound ratio was 5:1—15:1,which had a better effect on improving soil water-soluble ions.Taken together,the T2 and T3 treatments with a lactose peptide dosage of 225 kg/ha and a lactose peptide and inositol compound ratio of 5:1~10:1 were the best in terms of saving cost and maintaining the improvement effect.

In this research,a field orientation experiment on sorghum-maize rotation was conducted.The effects of different fertilization conditions on the growth,nutrient,soil enzyme activity and microbial activity of sorghum was studied.The experimental results showed that different fertilizer could significantly increase the jointing stage of sorghum plant height,stem diameter,number of pieces and index pages visible leaf area,as well as sorghum yield and grain weight per spike (P<0.05).Each processing production order of IF+M+S > IF+M > M+S > IF > CK,compared to the control,the range of yield increase of sorghum in different fertilization levels were 80.6%-120.7%,respectively,reaching a significant level,and among which IF+M+S treatment was the best.All values of inorganic fertilizer treatments were slightly higher than that of no fertilization treatment. The organic fertilizer treatment increased the soil nutrients and organic matter content of sorghum, compared with the inorganic fertilizer treatment. The total N, available P, available K, organic matter of IF+M+S treatment were 1.95, 10.36, 2.01, 1.83 times of CK, respectively (P<0.05). Soil enzyme activity of fertilization treatments in different growth periods was higher than no fertilization (CK),in which the most was the treatment of IF+M+S,activity of alkaline phosphatase in jointing stage and harvest stage,urease in harvest stage,invertase in jointing stage,flowering stage and harvest stage were all significantly higher than that of inorganic fertilizer treatment (P<0.05).The application of organic fertilizer or application combined with inorganic fertilizer could improve the soil microbial community functional diversity and the capability of utilizing carbon sources.And the treatments containing organic fertilizer and straw manure were more conducive to improve soil microbial diversity than other organic fertilizer treatments.

This study aims to explore the effects of reduced nitrogen application combined with organic fertilizer on soil carbon and nitrogen contents in the 0—60 cm layer of fragrant pear orchards,as well as the yield and quality of Korla fragrant pears,and to propose the optimal rate of reduced nitrogen application and matching ratio of organic fertilizer.Using 10—12-year-old Korla fragrant pear trees as test materials,a 3-year continuous experiment was carried out.The experiment set up a conventional nitrogen application treatment(denoted as N,with 300 kg/ha of nitrogen applied),three reduced nitrogen application treatments(denoted as N1,N2,N3,which reduced nitrogen by 10%,20%,and 30% respectively compared with the conventional nitrogen application treatment),and two organic fertilizer treatments(denoted as OF1 and OF2,with 22 500,33 750 kg/ha of sheep manure applied respectively).These treatments were combined to form six integrated treatments:N1F1,N2F1,N3F1,N1F2,N2F2,and N3F2.The soil carbon and nitrogen contents,soil carbon-to-nitrogen ratio(C/N),as well as the yield and quality of Korla fragrant pears were determined.The result showed that N1F1,N1F2,N2F2,and N3F2 treatments significantly increased the contents of total soil carbon,soil organic carbon,soil inorganic carbon,soil microbial biomass carbon(SMBC),soil nitrate nitrogen,and soil ammonium nitrogen in the orchard.They also increased the soil C/N ratio,the contents of soluble sugar and vitamin C in pear fruits,decreased the total acid content in fruits,and had no significant effect on pear yield.The N2F1 treatment significantly promoted the contents of soil nitrate nitrogen and ammonium nitrogen but had no significant effect on pear yield or quality.The N3F1 treatment significantly inhibited the contents of soil carbon fractions and pear yield and reduced the soluble sugar content in fruits.Correlation analysis showed that soil nitrate nitrogen,ammonium nitrogen,organic carbon,inorganic carbon,total nitrogen,total carbon,SMBC,and soil microbial biomass nitrogen(SMBN)were significantly or extremely significantly correlated with pear quality;the soil C/N ratio was significantly or extremely significantly negatively correlated with pear yield and quality.Among these factors,soil organic carbon,total nitrogen,nitrate nitrogen,and ammonium nitrogen had more prominent effects on pear yield and quality.Therefore,in subsequent fertilization management,improving the contents of soil organic carbon,total nitrogen,nitrate nitrogen,and ammonium nitrogen and regulating the soil C/N ratio can better increase the yield and improve the fruit quality of Korla fragrant pears.In the management of 10—12-year-old Korla fragrant pear trees,reducing nitrogen application by 20%—30% on the basis of the conventional nitrogen application rate while applying organic fertilizer at 33 750 kg/ha is beneficial.This measure regulates soil carbon and nitrogen contents,improves pear quality,reduces chemical fertilizer input to alleviate soil pollution,and ensures the health of the soil environment.

To provide theoretical basis and technical support for rational nitrogen fertilizer management in high-yield cultivation of hybrid wheat,this study aims to investigate the effects of nitrogen application rate on yield formation,dry matter accumulation and distribution,nitrogen absorption and utilization,as well as the nitrogen absorption ratio of wheat fertilizers in two-line hybrid wheat.From 2020 to 2021,three two-line hybrid wheat combinations and one conventional variety were used as materials.A split plot design was adopted,with nitrogen (labeled with ¹⁵N urea) treatment as the main zone and varieties as sub zones.Four nitrogen level experiments were set up at N0,N120,N180,and N240.The dry matter accumulation and distribution,plant nitrogen absorption and utilization,and grain yield of wheat organs were analyzed and measured under different treatments during the flowering and maturity stages.The results demonstrated that a highly significant effect of nitrogen application rate and combination (variety) on wheat yield and yield components.Compared with the conventional varieties Jingdong 17,the average yield of Jingmai 21 and BH9613 increased by 10.47% and 4.07% respectively,mainly due to their higher number of spikes and grains per ear.The application of nitrogen fertilizer significantly increased the number of spikes and grains per ear of wheat,but reduced the thousand grain weight.The application of nitrogen fertilizer to four varieties significantly increased the accumulation of dry matter in wheat during the flowering and maturity stages.The dry matter weight of various organs in wheat during the flowering stage was as follows:stem>leaf>spike,and during the maturity stage,it was as follows:grains>stem>spike-stalk+glume >leaf.The average values of nitrogen fertilizer agronomic utilization efficiency and nitrogen fertilizer partial productivity under different nitrogen application rates were as follows:Jingmai 21>BH9613>Jingdong 17>BH3606,which was consistent with the yield trend.The ¹⁵N atomic percentage of the four combinations (varieties),the nitrogen content from fertilizer,and the proportion of nitrogen from fertilizer all showed the following order:grains>straw,and they significantly increased with the increase of nitrogen application rate.Compared with Jingdong 17,the proportion of soil nitrogen in the three hybrid combinations (varieties) significantly increased,indicating that hybrid wheat had stronger tolerance to barrenness from the perspective of nitrogen utilization.After comprehensive consideration and analysis,the nitrogen application rate of N240 significantly increased wheat yield compared to other treatments,making it the optimal nitrogen fertilizer application rate for wheat cultivation.The comprehensive performance of the two hybrid combinations (varieties) of Jingmai 21 and BH9613 is better than the performance of the control Jingdong 17.

To investigate the effects of climate warming and combined application of organic and inorganic fertilizer on soybean growth and yield,field experiments were conducted using infrared radiation warming systems to simulate temperature elevation.The experimental design included two temperature levels(T0:Ambient temperature;T1:Warming by 2.9 ℃)and two fertilization regimes(SF:Sole inorganic fertilizer;OF:Combined organic-inorganic fertilizer),aiming to examine the impacts of warming and fertilization practices on soybean dry matter accumulation,photosynthetic rate,leaf enzyme activities,and yield.Results demonstrated that compared to ambient temperature,warming shortened the pre-flowering and post-flowering growth periods by 3—4 d,5—6 d,respectively.Warming significantly reduced leaf nitrate reductase(NR)and glutamine synthetase(GS)activities during the pod-filling stage,decreased leaf area index(LAI)by 9.0%—13.7%,and suppressed net photosynthetic rate,collectively leading to 4.1%—19.3% reductions in post-flowering plant height and aboveground dry matter accumulation.In contrast,the combined organic-inorganic fertilization enhanced NR and GS activities,improved post-flowering photosynthetic efficiency,promoted plant growth,and increased the aboveground dry matter accumulation by 4.1%—15.3% compared to sole inorganic fertilization,with a significant interaction observed between NR and alanine aminotransferase activities.Yield analysis revealed that warming caused 9.7%—16.6%,13.3%—19.0% declines in pods per plant and grains per plant,respectively,resulting in 13.7%—21.1% yield reductions.Conversely,organic-inorganic fertilization increased grains per plant by 12.5% and pods per plant by 9.9%—10.5%,achieving 7.6%—10.8% yield improvements.Notably,significant positive correlations were detected among LAI,photosynthetic rate,nitrogen metabolism enzyme activities,and final yield.These findings demonstrate that climate warming inhibits post-flowering photosynthetic efficiency and aboveground growth in soybeans,while integrated organic-inorganic fertilization partially mitigates warming-induced yield losses through enhancing enzyme activities and photosynthetic performance,providing critical insights for adaptive agricultural practices under global warming scenarios.

To clarify the effects of different tillage methods on soil moisture dynamics changes and maize yield under the condition of straw return to field in the black soil area along the foothills of Daxing'anling,based on six consecutive years of tillage positioning experiments,this study analyzed the effects of seven types of tillage methods,namely,full-crushing and deep-tillage (SCD),full-crushing and shallow-tillage (SSS),full-crushing and deep-tillage (SCS),full-crushing and re-harrowing (SCR),full-crushing and rotary tillage (STR),full-crushing and no-tillage (NTS),and conventional tillage without returning straw to the field (CK)on soil moisture characteristics,water consumption,water use efficiency,and agronomic traits and yield of maize in the 0—60 cm soil layer at different growth stages of maize in each treatment.The results showed a bimodal pattern of soil quality moisture content in 2022 and 2023.0—10 cm soil layer soil quality moisture content was significantly higher than that of CK,and the NTS treatment had the highest soil quality moisture content in several periods.10—20 cm soil layer soil quality moisture content was lower than that of CK in the SSS and NTS treatments at the jointing stage,and soil quality moisture content was higher than that of CK in the 20—40 cm and 40—60 cm soil layers in 2022 and 2023 for all the treatments.In 2022 and 2023,maize plant height in all treatments except NTS treatment was significantly higher than CK at different growth stages.The SCD treatment was the tallest and the NTS treatment was the shortest at mature stage.Leaf area index (LAI) varied little among treatments at seedling stage of maize,STR treatment had the highest LAI after the jointing stage,and all treatments had significantly higher LAI than NTS treatment at the big trumpet stage.Dry matter accumulation in all treatments except for the SCS,NTS treatment was significantly higher than in CK,and dry matter accumulation was highest in the SCD treatment and lowest in the NTS treatment at mature stage.All tillage treatments increased maize yield and water use efficiency compared with CK,but the SCD treatment was significantly higher than CK.Comprehensive analysis of the indexes showed that the two tillage methods of full-crushing and deep-tillage and full-crushing and shallow-tillage were favorable to improve soil structure,maize yield and water use efficiency in the black soil area along the foothills of Daxing'anling.

The mechanism of the effect of phosphorus application rate on the growth,yield formation and phosphorus fertilizer utilization rate of high-yield maize in Xinjiang under the condition of drip irrigation and fertilizer integration was clarified,in order to provide a theoretical basis for the high and stable yield of maize in Xinjiang and the green sustainability of fertilizer reduction and efficiency increase.The experiment was carried out in the maize high-yield demonstration base of Qitai Farm in Xinjiang from 2023 to 2024.Under the condition of drip irrigation and fertilizer integration,six phosphorus application levels were set up:no phosphorus fertilizer(P₀),pure phosphorus 60 kg/ha (P₆₀),90 kg/ha(P₉₀),120 kg/ha (P₁₂₀),150 kg/ha (P₁₅₀)and 180 kg/ha(P₁₈₀,CK).The changes of leaf area index(LAI),photosynthetic potential(LAD),dry matter accumulation,harvest index(HI),ear traits,yield and yield components of maize with water and fertilizer integration of dense planting drip irrigation were analyzed,and the effect of phosphorus application rate on yield and phosphorus fertilizer utilization rate of maize with dense planting drip irrigation in Xinjiang was clarified.The results showed that under the condition of drip fertigation and phosphorus application,the maize yield increased first and then tended to be stable with the increase of phosphorus application in the two years,and the yield was the highest(18.79—20.94 t/ha)at P₁₂₀ treatment.The amount of phosphorus application significantly affected the 1000-grain weight and grain number per ear of maize.The amount of phosphorus application mainly affected the length of maize ear bald tip.Compared with P₁₅₀ and P₁₈₀ treatments,the difference of ear bald tip length was not significant.During the critical growth period of corn,LAI showed a trend of first increasing and then stabilizing with increasing phosphorus fertilizer application rates.The LAI of maize under P₁₂₀ treatment at silking stage was 7.56—7.81,which was not significantly different from P₁₅₀ and P₁₈₀ treatments,but was significantly reduced by 21.54% under P₀ compared with P₁₂₀.In addition,the dry matter accumulation before and after anthesis of maize treated with P₁₂₀ was not significantly different from that of P₁₅₀ and P₁₈₀ treatments,which was 37.91% and 93.88% higher than that of P₀,respectively.In summary,drip fertigation and phosphorus application significantly affected LAI,LAD,pre-anthesis and post-anthesis dry matter accumulation and HI,shortened bald tip length,increased grain number per spike and 1000-grain weight,and then increased maize yield and phosphorus utilization efficiency,and realized the synergistic improvement of maize yield and phosphorus fertilizer utilization efficiency.

To investigate the effects of partially substituting chemical fertilizer with biochar-based organic fertilizer derived from cattle manure on N₂O emissions in summer maize fields and the underlying regulatory mechanisms,a field plot experiment was conducted from 2023 to 2024 at the Dishang Experimental Station of the Institute of Cereal and Oil Crops,Hebei Academy of Agriculture and Forestry Sciences.Four fertilization treatments were set up:CF(conventional nitrogen-phosphorus-potassium fertilizer),and COF1,COF2,and COF3,which replaced 15%,30%,and 45% of the chemical nitrogen in CF with an equivalent amount of nitrogen from biochar-based organic fertilizer derived from cattle manure,respectively.The study analyzed the effects of different fertilization regimes on N₂O emissions,plant nitrogen uptake,soil physicochemical properties,abundance of nitrogen-cycle-related functional genes,and grain yield.The results showed that:(1)Compared with CF,the cumulative N₂O emissions under COF1,COF2,and COF3 treatments were significantly reduced by 39.4%,42.5%,and 43.8%,respectively.While reducing emissions,COF1 and COF2 increased plant nitrogen uptake by 45.9% and 24.5%,and yield by 10.6% and 11.7%,respectively.(2)COF1 and COF2 significantly promoted the formation of water-stable aggregates(WSA)(increased by 12.7% and 16.5% compared with CF,respectively)and reduced the abundance of key denitrification functional genes(norB,norC,narH),while enhancing the expression of genes related to dissimilatory nitrate reduction to ammonium(DNRA)(napA,napB),thereby promoting the accumulation of soil nitrate and ammonium nitrogen.(3)COF1 and COF2 increased root biomass and the activities of nitrate reductase and glutamine synthetase in roots and leaves,synergistically improving plant nitrogen uptake and utilization.Correlation analysis further revealed that soil WSA formation was significantly negatively correlated with the abundance of key denitrification genes(norB/C,narH),while positively correlated with plant nitrogen uptake,root biomass,and nitrogen metabolism enzyme activities.In conclusion,replacing 15%—30% of chemical fertilizer with biochar-based organic fertilizer derived from cattle manure can directly inhibit the denitrification process and reduce N₂O emissions by promoting the formation of water-stable soil aggregates.Simultaneously,it indirectly reduces N₂O emissions by enhancing the DNRA pathway and plant nitrogen uptake capacity,which competes with denitrification for nitrate substrates.

To investigate the effects of optimizing basal-to-topdressing ratios combined with nitrogen application rates on nitrogen metabolism and nitrogen uptake/utilization in flue-cured tobacco,a field experiment was conducted using the cultivar Yueyan 97.Five treatments were designed:conventional basal-to-topdressing ratio (6∶4)+conventional nitrogen rate (CK),basal-to-topdressing ratio (4∶6)+conventional nitrogen rate (T1),basal-to-topdressing ratio (4∶6)+10% nitrogen reduction (T2),basal-to-topdressing ratio (4∶6)+20% nitrogen reduction (T3),and basal-to-topdressing ratio (4∶6)+30% nitrogen reduction (T4).It analyzed the impacts of these treatments on nitrogen metabolism,photosynthetic characteristics,dry matter accumulation,nitrogen uptake,nitrogen use efficiency,and nitrogen balance.The results showed that after optimizing the basal-to-topdressing ratio to 4∶6,the activities of key nitrogen metabolism enzymes,including glutamate dehydrogenase (GDH),aspartate transaminase (AST),and ferredoxin-glutamate synthase (Fd-GOGAT),were all higher than those under the traditional basal-to-topdressing ratio of 6∶4.When combined with nitrogen reduction treatments,the activities of nitrogen metabolism enzymes decreased.Specifically,T2 (10% nitrogen reduction) showed no significant difference from CK,while T3 and T4 (20%—30% nitrogen reduction) exhibited marked declines in enzyme activity.Optimizing the basal-to-topdressing ratio to 4∶6 also improved photosynthetic rate,SPAD values,dry matter accumulation,and nitrogen accumulation,with significant differences observed during the late growth stages.Furthermore,the optimizing 4∶6 ratio significantly enhanced nitrogen use efficiency.Compared to CK,nitrogen agronomic efficiency,partial factor productivity,recovery efficiency,and economic utilization efficiency increased by 20.68%,6.89%,4.06 percentage points,and 3.78 percentage points,respectively.Nitrogen reduction treatments reduced soil nitrogen surplus by 17.04—33.36 percentage points compared to CK.In conclusion,optimizing the basal-to-topdressing ratio from 6∶4 to 4∶6 in southern tobacco-growing regions enhances nitrogen metabolism during mid-to-late growth stages,improved photosynthetic performance,promotes dry matter and nitrogen accumulation,and increased nitrogen use efficiency.Coupled with 10% reduction in fertilizer can also reduce fertilizer input,mitigetes soil nitrogen surplus,and prevent environmental risks.

To investigate the influence of green manure cultivation on the carbon and nitrogen content of saline-alkali soil under freshwater leaching,a field experiment was conducted from October 2021 to May 2022.Three treatments were set up:winter fallow(T1),Dongmu 70 rye(T2),and rape(T3).The spatial distribution of soil organic carbon(SOC),nitrate nitrogen($\mathrm{NO}_{3}{ }^{-}-\mathrm{N}$),and ammonium nitrogen($\mathrm{NH}_{4}^{+}-\mathrm{N}$)in the soil and leachate were measured.The results revealed that in the 0—30 cm soil layer,the soil organic carbon content of T1,T2,and T3 increased from 6.20,6.58,7.24 g/kg before leaching to 6.48,7.39,8.06 g/kg after leaching,representing an increase of 4.41%,12.20%,and 11.23%,respectively.After freshwater leaching,the nitrate nitrogen content in the 0—60 cm soil layer of T1 was significantly higher than that of T2 and T3.In the 0—30 cm soil layer,the respective reductions for each treatment were 42.42%,3.85%,and 10.84%.In the 60—90 cm soil layer,the reductions were 1.38%,7.96% and 18.11%.There were no significant differences in ammonium nitrogen content among the different treatments before leaching,but after leaching,the highest ammonium nitrogen content was observed in T2.In conclusion,after leaching irrigation,the soil organic carbon content in different soil layers increased compared to before leaching,while soil nitrogen showed a significant decrease.Analysis of nitrogen content in the soil and leachate indicated that the main nitrogen loss caused by leaching irrigation was in the form of nitrate nitrogen.Compared to winter fallow farmland,the cultivation of rapeseed green manure had a significant effect on increasing soil nitrogen content,while Dongmu 70 green manure was the the most effective in reducing soil nitrogen loss.

In order to improve the nitrogen use efficiency and corn yield during the whole growth period of maize, it provides a reference for the high-yield nitrogen fertilizer operation model of maize in Heilongjiang Area. Ratio (CK:blank control; T1:50% base fertilizer+50% flowering fertilizer; T2:30% base fertilizer+40% jointing fertilizer+30% flowering fertilizer; T3:20% base fertilizer+60% jointing fertilizer+20% flowering fertilizer; T4:10% basal fertilizer+60% jointing fertilizer+30% flowering fertilizer) on the change of soil inorganic nitrogen content, nitrogen balance, nitrogen accumulation at different growth stages, nitrogen use efficiency and corn yield. The results showed that compared with the control group, T2, T3, and T4 effectively increased the inorganic nitrogen content of the soil plow layer during the filling stage and the mature stage; in terms of nitrogen balance, T2, T3, and T4 were significant difference than the T1 treatment. Reduced the apparent nitrogen loss, of which T4 apparent nitrogen loss was the lowest; compared with T1, reducing the ratio of nitrogen to topdressing significantly increased the nitrogen accumulation during the flowering-maturity period, and the nitrogen accumulation during the filling-maturity period T4 was the highest treatment; compared with T1, T2, T3, and T4 significantly increased the nitrogen absorption and utilization rate, agronomic utilization rate and partial productivity of maize, and the increase ranges was 16.66%-22.47%, 17.80%-35.76%, 4.93%-9.90% (Xianyu 335) and 6.55%-24.46%, 8.23%-36.94%, 2.02%-5.44% (Tiannong 9); reducing the ratio of nitrogen fertilizer to topdressing (T2, T3, T4) yields significantly higher than the traditional nitrogen application treatment T1, T3 had the highest yield, which was 9.90% (Xianyu 335) and 8.86% (Tiannong 9) compared with T1. In summary, under the experimental conditions, when the total nitrogen application rate was 210 kg/ha, 20% basal fertilizer+60% jointing fertilizer+20% flowering fertilizer was the best nitrogen basal dressing ratio.

Based on the long-term located fertilization experiment of Laiyang, Shandong Province, China, began in 1978, to study the transport and accumulation characteristics of nitrate nitrogen and ammonium nitrogen in the Fluvo-aquic soil and its relationship with the summer maize yield.The test set organic fertilizer(M), nitrogen fertilizer(N)2 factors, 3 levels, 9 treatment;3 levels of organic fertilizer(M):M₀(0 t/ha), M₁(30 t/ha), M₂(60 t/ha), and 3 levels of nitrogen fertilizer(N):N₀(0 kg/ha), N₁(138 kg/ha), N₂(276 kg/ha).After summer corn harvest in 2014 and 2015, the contents of nitrate nitrogen and ammonium nitrogen in soil 0-20, 20-40, 40-60, 60-80 and 80-100 cm were measured respectively, the accumulation of nitrate nitrogen, ammonium nitrogen in different soil depth of 0-100 cm and the summer corn yield were calculated.The results showed that the amount of nitrate nitrogen, ammonium nitrogen and its accumulation amount in soil could be improved by applying organic fertilizer or nitrogen fertilizer.In the 0-100 cm soil layer, the vertical migration trends of nitrate nitrogen of different treatments were different, but the vertical migration trend of ammonium nitrogen were basically the same.Compared with chemical fertilizer, application of organic fertilizer could slow nitrate to the deep soil leaching, but both of ammonium nitrogen to influence the trend of migration in deep soil was not obvious.Long-term application of organic fertilizer, nitrogen fertilizer on nitrate nitrogen, ammonium nitrogen accumulation amount of the impact of extremely significant level, there was extremely significant interaction effect on the accumulation of nitrate nitrogen in soil.Compared with the M₀N₀(CK), the accumulation of nitrate nitrogen and ammonium nitrogen in the addition of fertilization treatments were significantly respectively increased by 112%-396% and 69%-259% at P<0.05.In 0-20, 0-40, 0-60, 0-80, 0-100 cm in each soil layer, the nitrate nitrogen accumulation and the ammonium nitrogen accumulation had different linear relationship with summer maize yield.Research showed that rational application of organic and inorganic fertilizers could reduce the accumulation of nitrate nitrogen and ammonium nitrogen in soil and the leaching, and it is advantageous to improve the yield of crops, maintain the stability of the soil ecosystem, promote the sustainable development of agriculture and protect the groundwater resources.

In order to explore the effects of cattle manure on soil salinity and sodicity on the sodic soil in long-term experiments,the experiments were performed in a randomized complete block design with four treatments;soils that received manure applications for 8,12,18 years were used as the experimental treatments,and soil that did not receive cattle manure application was used as the control treatment(CK).The results showed that the application of cattle manure to saline-sodic soil resulted in a reduction in the bicarbonate ion(HCO₃^-)contents,the elimination of carbonate ions(CO₃^2-),the decrease in soil bulk density(ρ_b),the increases in soil porosity(f_t)and soil organic matter(SOM),the decreases in the exchangeable and soluble sodium ion (Na⁺)contents associated with increases in the exchangeable calcium ion(Ca²⁺),soluble potassium ion(K⁺),and magnesium ion(Mg²⁺)contents compared to those in untreated soil.The soil exchangeable sodium percentage(ESP)and pH were both significantly and positively correlated with the exchangeable Na⁺ and HCO₃^-,and CO₃^2- contents,and soil pH was significantly and negatively correlated with SOM.Regression analysis showed that the dominant factors affecting the sodium absorption ratio(SAR)were the soluble Mg²⁺ and Na⁺ contents in the soil.Pearson correlation analysis showed that there were significantly negative correlation between the accumulated amount of cattle manure among the indicators of soil salinization degree,such as pH,EC,ESP and SAR.It was concluded that long-term manure application significantly decreased the soil pH,ESP,electrical conductivity(EC)and SAR due to the replacement of soil colloidal Na⁺ with Ca²⁺,the leaching of soil soluble salts from the topsoil and changes in the soil soluble salt ion composition.These outcomes were likely due to the decrease of ρ_b associated with increase of f_t and Ca²⁺ and Mg²⁺ contents caused by annual manure application.

This study investigated the accumulation and distribution of dry matter,nitrogen(N)and zinc(Zn)of summer maize under N and Zn fertilization,to provide a basis for reasonable application of zinc fertilizer and combined fertilization.Split-split design was used with three N rates(90,180,225 kg/ha N)as the main factor,two Zn rates(0,4.5 kg/ha ZnSO₄·7H₂O)as the second factor,two varieties(ZD958 and GSY66)as the third factor.The effect of N and Zn application on the grain yield,dry matter accumulation dynamic and N and Zn absorption,accumulation and distribution of each organ of different maize varieties by field experiment.The results showed that the grain yield achieved 9.77,10.42 t/ha under the N rates of 180,225 kg/ha,respectively,increased by 18.0% compared with 90 kg/ha.The treatment of 225 kg/ha N had the highest plant dry matter accumulation after silking,while the treatment of 90 kg/ha had higher ratio of cob and grain dry matter at the mature stage.Highest N concentration in each organ,Zn concentration in the stem and N and Zn accumulation in the leaf and grain were obtained in the treatment of 225 kg/ha,while highest Zn concentration in the sheath,bract and grain and ratio of grain N and Zn were found in the treatment of 90 kg/ha.No effect was found in the grain yield and dry matter accumulation and distribution under two Zn treatments.Zn application significantly increased N and Zn concentration and accumulation but decreased distribution ratio of grain N and Zn by 6.93,6.86 percentage points,respectively.Relative to GSY66,ZD958 had higher grain yield and dry matter ratio,and increased dry matter by 29.2% at maturity.Besides this,ZD958 decreased grain N and Zn concentration by 8.9% and 5.3%,respectively,but improved grain accumulation and distribution ratio.Correlation analysis showed that grain yield and N concentration in the stem,leaf and grain were significantly positively correlated.There was also a significantly or extremely significantly positive correlation between Zn concentration in the leaf and N concentration in the sheath and grain,between Zn concentration in the cob and N concentration in the sheath,cob and bract.These results suggested that combination of N and Zn fertilizers could increase yield and plant dry matter accumulation,enhance the N and Zn absorption and accumulation in each organ especially grain,but decrease distribution ratio of N and Zn in the grain.

In order to explore the effects of nutrient expert (NE) management on nitrogen (N) use efficiency and soil organic carbon (SOC) sequestration in the wheat-maize rotation system and improve its management practices, a long-term experiment was set up in 2009 to compare NE management with farmer's practice (FP) management. Through 9-years experiment, the crop yield, N use efficiency, SOC content, SOC sequestration rate and SOC sequestration efficiency were measured and analyzed. The advantages of long-term NE management in wheat-maize crop rotation system were evaluated. The results showed that long-term NE management reduced the amount of N fertilizer application rate, compared with FP management, but maintained the crop yields (no significant difference with FP). Compared with FP management, the average accumulative recovery efficiency of N, agronomic efficiency of N, and partial productivity of N in NE management system increased by 7.4 percentage points, 39.7%, and 28.4% in maize production system, and increased by 8.0 percentage points, 28.9%, and 32.8% in wheat production system, respectively After 9-years experiment, both NE and FP increased the SOC contents, with NE management increased faster than FP. The annual SOC contents rise rates of NE treatment in 0-5 cm, 5-10 cm and 10-20 cm soil profile were 0.28, 0.27, 0.34 g/(kg·a), respectively, which were 7.7%, 68.8% and 126.7% higher than those of FP treatment. The average annual carbon input of NE and FP treatment from straw returning were 8.5, 8.7 t/(ha·a), respectively, and the SOC sequestration rates were 1.35, 0.68 t/(ha·a),respectively, and the SOC sequestration efficiencies were 18.6% and 0.4%, respectively, which shown a significant difference. NE management could improve N use efficiency and increase SOC sequestration. Long-term NE management is one of the important measures for fertilizer saving, efficiency strengthen and SOC pool richen in wheat-maize rotation system. It would play a crucial role in ensuring food security and realizing agriculture green development.

The effects of castor cake meal fertilizer on soil fertility and peanut yield and quality were studied.Using the peanut variety Silihong in Northeast China as the experimental material,a two-year field positioning experiment(2022 and 2023)was carried out,with no fertilization(CK),castor cake meal fertilizer(B1:2 520 kg/ha,B2:5 040 kg/ha,B3:10 080 kg/ha),chemical fertilizer(F1:175 kg/ha,F2:350 kg/ha,F3:700 kg/ha),cow manure(N1:3 724 kg/ha,N2:7 448 kg/ha,N3:14 896 kg/ha).A total of 10 treatments were used to analyze the effects on soil fertility and peanut yield and quality.The results showed that the application of castor cake meal fertilizer in 2022 and 2023 could improve soil nutrients to varying degrees.B3 treatment could significantly reduce soil pH value,and the effect of soil organic carbon,total nitrogen,total phosphorus,total potassium,alkali-hydrolyzed nitrogen,basic phosphorus,and available potassium content were the best.Compared with CK,the average increase was 67.58%,64.56%,70.55%,11.33%,75.76%,149.97% and 116.84%,respectively.Compared with CK,chemical fertilizer and cow manure made soil organic carbon,total phosphorus and basic phosphorus content increase by an average of 5.94% and 11.48%,16.67% and 16.67%,33.35% and 23.94%,respectively.The full fruit weight per plant,100 fruit weight,100 grains weight of peanut with B3 treatment were better than that treated with chemical fertilizer and cow manure,which increased by an average of 105.43%,127.91%,19.54% and 22.75%,16.79%,24.17%,respectively.B3 treatment had the highest peanut yield,which was 1 876.22 kg/ha higher in 2023 than 2022.B1 treatment increased the contents of peanut fat and oleic acid and decreased the content of linoleic acid and palmitic acid,compared with CK,the content of peanut fat and oleic acid increased by 6.07 and 4.23 percentage points,and the contents of linoleic acid and palmitic acid decreased by 1.79 and 0.89 percentage points.The contents of soil organic carbon,total nitrogen and alkali-hydrolyzed nitrogen were positively correlated with peanut fat content.The contents of soil organic carbon,total nitrogen and alkali-hydrolyzed nitrogen were significantly positively correlated with peanut yield.In conclusion,castor cake meal fertilizer could improve soil,increase peanut yield and quality.

To investigate the phosphate-solubilizing effects of different combinations of phosphate-solubilizing bacteria(PSB)and their impact on maize growth and phosphorus uptake,a pot experiment was conducted using three bacterial strains with distinct taxonomic classifications and phosphate-solubilizing capacities:Pseudomonas frederiksbergensis P4-5,Arthrobacter oryzae P5-41,and Bacillus aryabhattai P3-50.A non-inoculated treatment served as the blank control(CK),and the experimental treatments included:single inoculation with P4-5(Pf),single inoculation with P5-41(Ao),single inoculation with P3-50(Ba),dual inoculation with P4-5 and P5-41(Pf×Ao),dual inoculation with P4-5 and P3-50(Pf×Ba),dual inoculation with P5-41 and P3-50(Ao×Ba),and combined inoculation with P4-5,P5-41,and P3-50(Pf×Ao×Ba).The effects of these inoculation treatments on maize root morphology,shoot growth,phosphorus uptake,and indole-3-acetic acid(IAA)secretion capacity by the bacterial strains were analyzed.The results indicated that,compared to the CK,all PSB inoculations significantly increased maize stem diameter,leaf SPAD value,shoot biomass,and phosphorus uptake.Furthermore,they also significantly enhanced rhizosphere alkaline phosphatase activity(except for single inoculation with Pf and Ba,respectively)and reduced soil available phosphorus content(except for single inoculation with Ba).Among these treatments,the combined inoculation of Pf×Ao×Ba exhibited the best overall performance.This treatment secreted high concentrations of IAA,optimized maize root morphology(increasing root length,volume,surface area,and number of root tips),and significantly increased rhizosphere alkaline phosphatase activity,thereby promoting the mineralization of soil organic phosphorus and consequently enhancing maize growth and phosphorus uptake.In conclusion,the combined inoculation of Pf×Ao×Ba significantly promoted maize growth and improved phosphorus nutrition through a dual mechanism:optimizing root morphology by increasing root length,volume,surface area,and root tip number through IAA secretion,and effectively mineralizing soil organic phosphorus by enhancing alkaline phosphatase activity.

The effects of tillage depth and organic fertilizer rates on photosynthetic characteristics,yield formation,and economic benefits of wheat were explored to provide a theoretical and technical basis for fluvo-aquic soil or similar soil types.The two-factor split-plot field experiment was conducted in the typical fluvo-aquic soil area of Qihe County,Dezhou City,Shandong Province from 2022 to 2024,where the tillage depth 15-20 cm(D1)and tillage depth 30-35 cm(D2)were assigned to the main plots,and the organic fertilizer rates of 800(L),1 200(M),and 1 600 kg/ha(H)were assigned to the subplots.The photosynthetic characteristics,aboveground dry matter accumulation characteristics and yield composition,in wheat were tested in fluvo-aquic soil under different tillage depths and organic fertilizer rates.Both D2M and D2H treatments were beneficial to improve the yield and yield components of wheat,and the spike number,kernels per spike,1000-grain weight,and grain yield significantly increased by 5.5%-8.5%,3.5%-12.1%,6.7%-13.2% and 6.6%-12.8%,compared with other treatments,respectively.D2M and D2H treatments also stabilized or increased the above-ground dry matter accumulation at jointing,anthesis,and maturity stages by improving the above-ground dry matter accumulation rate at each growth stage,which was 9.0%-22.1%,8.9%-25.8% and 10.7%-24.3% higher than averaged across the two years of other treatments,respectively.Compared with D1,D2 was more conducive to promoting the effect of organic fertilizer on the SPAD of leaves at different growth stages.Under D2M and D2H treatments,higher chlorophyll content could be maintained from the mid- to late-filling stages.Under M and H organic fertilizer application rates,the Pn of leaves at different growth stages of D2 was significantly higher than that of D1.At jointing,booting,flowering,mid-filling,and late-filling stages,on average over the two years,D2M and D2H increased significantly by 12.0% to 16.7%,13.7% to 16.8%,13.8% to 19.7%,20.2% to 25.8%,and 24.6% to 44.8%,respectively,compared with D1M and D1H.Under the same organic fertilizer application rates,the difference in leaf LAI between the two tillage depths gradually increased with the progression of the growth process.D2M and D2H performed best at anthesis and mid-filling stages,increasing by 13.2% to 27.2%,and 13.4% to 29.4%,respectively,compared with other treatments on average over the two years.In conclusion,both D2M and D2H treatments could enhance the photosynthetic characteristics of plants and the above-ground dry matter accumulation ability,thereby optimizing the yield components and achieving the drastically improvement of wheat yield.However,there were no significant differences in the indices between D2M and D2H treatments.Therefore,considering resource conservation,this study suggests that the combination of a tillage depth of 30-35 cm and an organic fertilizer application rate of 1 200 kg/ha can achieve wheat high yielding.

In order to the issues of carbon-nitrogen balance and emission reduction in greenhouse soil,a field experiment was carried out to explore the impacts of the combination of summer catch sweet corn and biochar on nitrogen absorption and carbon emission reduction in greenhouse soil.Four treatments were designed for this experiment:control(T1),catch crop(T2),biochar(T3),atch crop+iochar(T4).The research results showed that the dry biomass and nitrogen absorption of T4 corn were 10.18% and 9.49% higher than those of T2,respectively.The organic carbon in the surface soil of T3 and T4 increased by 25.26% and 50.01% compared to before the experiment,respectively.The total nitrogen in the surface layer of T4 decreased by 10.13%,and the C/N increased to 14.9.The nitrate nitrogen in the 60—80 cm and 80—100 cm soil layers of T4 decreased by 13.02% and 5.68% compared to before the experiment,with a significantly greater reduction than other treatments.The non-root microbial biomass carbon and nitrogen of T4 increased by 26.00% and 20.33% compared to the control,with the increase in the non-root area being lower than that in the non-root area.The average CO₂ emission of T4 was 603.90 mg/m³,which was 24.61% lower than that of the control.In summary,the combination of fallow sweet corn and biochar significantly promoted nitrogen absorption,increased microbial biomass carbon and nitrogen,reduced carbon and nitrogen leaching and emissions,and improved soil C/N,providing theoretical basis support for carbon and nitrogen management in the summer fallow period of facility farmland.

To explore the effects of fertilizer reduction and organic fertilizer application on physicochemical properties and microbial community structure of tobacco-planting soil,and provide theoretical reference for fertilizer reduction and rational application of organic fertilizer in tobacco production.Using conventional fertilization without organic fertilizer as control(CK),Illumina high-throughput sequencing technology combined with bioinformatics,the changes of soil physical and chemical properties and microbial community structure under different treatments such as 10% reduction of fertilizer(T1),10% reduction of fertilizer+sesame cake fertilizer(T2),10% reduction of fertilizer + humic acid fertilizer(T3),and 10% reduction of fertilizer + sesame cake fertilizer + humic acid fertilizer(T4)were analyzed.The results showed that compared with CK,soil nutrient content and soil enzyme activity decreased under T1 treatment,and soil physical properties were slightly improved.Combined with organic fertilizer,soil nutrient and physical properties were further improved,bulk density decreased,moisture content and porosity increased,and the contents of available phosphorus and available potassium under T2 and T4 treatment were significantly higher than those under CK and T1 treatment.The enzyme activity of soil treated with organic fertilizer increased significantly.Combined application of organic fertilizer increased the bacteria and fungi in tobacco-growing soil,among which the dominant bacteria were Proteobacteria and Actinobacteriota.Followed by Firmicutes,Bacteroidota,Chloroflexi and Acidobacteriota.The dominant fungal groups are Ascomycota,Anthophyta,Mortierellomycota,Chlorophyta,Ciliophora and Basidiomycota.The Alpha diversity index showed that the reduction of fertilizer decreased the richness of microbial community,but the combined application of organic fertilizer increased the diversity index of bacterial and fungal communities,and the bacterial community richness increased more significantly.RDA analysis showed that the important soil physicochemical factors affecting soil microbial community structure and diversity included organic matter,available potassium,alkali-hydrolyzed nitrogen,available phosphorus and soil physical properties,etc.Soil physicochemical factors had a greater impact on bacterial community structure.In conclusion,under the condition of fertilizer reduction,organic fertilizer combined with organic fertilizer can significantly improve soil nutrients,physical properties,soil enzyme activity and microflora structure,especially when combined with sesame cake fertilizer and humic acid fertilizer treatment.

To clarify the alterations of rice straw decomposition,nutrients release and chemical components in coastal saline paddy soils under different nitrogen (N) application rate,for optimizing the technology of straw returning and realizing the efficient utilization of straw resources in coastal areas.The experimental site was located in Caofeidian District,Tangshan City,Hebei Province.The decomposition characteristics of rice straw and its lignocellulose,as well as the nutrient release characteristics of N,phosphorus (P) and potassium (K) were studied,using a 360-day straw-bag burying method with four different N fertilizer levels,including N0 (0 kg/ha),N1 (225 kg/ha),N2 (300 kg/ha) and N3 (375 kg/ha).Pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) method was used to study the dynamic alterations of principal chemical components of the rice straw residues.The results showed that:the decomposition period of rice straw was divided into three stages,namely,rapid decomposition (0—30 d),slow decomposition (30—210 d) and slow decomposition (210—360 d),and the average decomposition rate of rice straw was 72.5% after 360 days with different N application rates.Increasing N application significantly increased the decomposition rate of rice straw.Compared with the N0 treatment,the N1,N2 and N3 treatments,increased the straw decomposition rate by 6.1, 7.4 and 9.2 percentage points,respectively.The trend of straw carbon (C) release rate was similar to that of straw decomposition rate,while the C release rate was only 43.2% at the end of the experiment.The nutrient release rates of rice straw were as follows:K>P>N.The N,P and K rapid release periods of rice straw was in the 0—30th (38.4%),0—60th (63.7%) and 0—15th (76.7%) days after straw decomposition,respectively.Both N and P of rice straw were enriched during the decomposition period.N application significantly increased the release of N from straw during the decomposition period,P in the early (0—15 d) and late (150—360 d) period,and K in the early period (0—15 d).Compared with the N0 treatment,the N1,N2,and N3 treatments,increased the straw N release by 6.6, 11.1, and 14.7 percentage points,P release by 2.2, 4.0, and 5.6 percentage points,and K release by 1.4, 2.1, and 2.8 percentage points,respectively.The lignocellulose decomposition rates of rice straw were as follows:hemicellulose>cellulose>lignin.Increasing N application significantly promoted the cellulose and hemicellulose decomposition rate of rice straw from day 0—90 and the lignin decomposition rate after day 90.Compared with the N0 treatment,the N1,N2,and N3 treatments,increased the cellulose decomposition rate of rice straw by 5.4, 7.3, and 8.4 percentage points, hemicellulose decomposition rate by 4.9, 6.4, and 7.4 percentage points,and lignin decomposition rate by 2.1, 5.1, and 5.7 percentage points, respectively.2-methoxy-4-vinylphenol,hydroxyacetone,2,3-dihydrobenzofuran,acetosyringone,eugenol,n-hexadecanoic acid,p-methylphenol,2,6-dimethoxyphenol,guaiacol,p-ethylphenol,and stigmasta-3,5-diene were the major (>1% relative) chemical components of straw residues during the decomposition period.Correlation analyses showed that straw decomposition rate,C release rate and cellulose,hemicellulose and lignin decomposition rates,were significantly positively correlated with eugenol,acetosyringone and 2,3-dihydrobenzofuran,while significantly negatively correlated with hydroxyacetone;straw P release rate was significantly positively correlated with hydroxyacetone and significantly negatively correlated with p-ethylphenol,eugenol and acetosyringone;straw K release rate was significantly correlated with p-ethylphenol,eugenol,acetosyringone and 2,3-dihydrobenzofuran,while significantly positively correlated with hydroxyacetone.In conclusion,increasing N application could promote the decomposition rates of rice straw and its lignocellulosic cellulose,and the nutrients release of straw N,P and K in coastal saline paddy field.The recommended optimal N application rate was 300 kg/ha under straw returning 10 500 kg/ha in coastal saline soils.p-ethylphenol,eugenol,acetosyringone,2,3-dihydrobenzofuran,hydroxyacetone,and stigmasta-3,5-diene could indicate the process of straw decomposition in straw residues.Py-GC-MS technique shows a good capability to monitor the chemical components alterations of straw residues,further deepening the understanding of straw decomposition mechanism.

This study systematically investigates the effects of silicon-modified biochar (MSC) on the chemical properties of acidic soil,organic carbon and silicon fractions,and the growth of tomato plants.Silicon-modified biochar was prepared,with a focus on investigating its impacts on carbon and silicon chemical fractions,and the availability in acidic soils;tomato growth and soil microbial activity were also evaluated.The results showed that silicon-modified biochar significantly increased soil pH,cation exchange capacity,electrical conductivity,available phosphorus and potassium.MSC also raised the levels of water-soluble sodium and iron in the soil and enhanced the activities of hydrogen peroxidase and sucrase enzymes,thereby improving soil quality.Both biochar modification and unmodified biochar significantly increased the content of different carbon fractions in the soil.Compared with unmodified biochar,silicon-modified biochar significantly increased soil microbial biomass carbon(21.9%) and water-soluble organic carbon (898.3%).Furthermore,silicon-modified biochar significantly increased the contents of soil available silicon,water-soluble silicon,free silicon,active silicon,iron-manganese-bound silicon and amorphous silicon by 362.6%,158.9%,18.1%,34.9%,193.8%,and 74.1%,respectively.Meanwhile,the application of biochar promoted the growth of tomato plants and the absorption of silicon nutrients,with modified biochar showing more pronounced effects.The accumulation of plant dry matter,silicon content,and absorption rate increased by 82.0%,98.9%,and 261.5%,respectively.In summary,silicon-modified biochar significantly affected the carbon and silicon chemical forms and transformation in the soil,increased soil effectiveness and enzyme activity,thereby promoting nutrient absorption and growth of crops,demonstrating its good potential application in agricultural production.

In order to explore the effect of partial replacement of chemical fertilizer by organic fertilizer on the ecological stoichiometric characteristics of soil carbon,nitrogen and phosphorus in the Loess Plateau of Eastern Qinghai,a field experiment was conducted with continuous cropping of potato(Qingshu 9).This field experiment was established in 2022 with five treatments,i.e.no fertilizer(CK),100% chemical fertilizer(T1),30% organic fertilizer+70% chemical fertilizer(T2),50% organic fertilizer+50% chemical fertilizer(T3),and 70% organic fertilizer+30% chemical fertilizer(T4).Soil contents of organic carbon,total nitrogen,total phosphorus,alkali-hydrolyzable nitrogen,available phosphorus,microbial biomass carbon,nitrogen,phosphorus and soil-microbial biomass ecological stoichiometry were determined.The results showed that compared with 2022,the contents of soil organic carbon,total nitrogen,total phosphorus,alkali-hydrolyzable nitrogen,available phosphorus and microbial biomass carbon,nitrogen and phosphorus in each fertilization treatment in 2023 showed an increasing trend,while the CK treatment showed a decreasing trend.Among different soil layers,the content of each index gradually decreased with the increase of soil depth.Among different treatments,according to the content of each index,the order was T3>T4>T2>T1>CK.In the 0—30 cm soil layer,the contents of soil organic carbon,total nitrogen,total phosphorus,alkali-hydrolyzable nitrogen,available phosphorus and microbial biomass carbon,nitrogen and phosphorus under T3 treatment were 6.88%,17.65%,17.88%,84.71%,77.01%,65.67%,80.07%,54.91% higher than those of CK,respectively.The soil C∶N and C∶P in each soil layer were the highest in the CK treatment.Among the four fertilization treatments,soil C∶N,microbial biomass C∶N and C∶P were the lowest in the T3 treatment.In addition to the 0—10 cm soil layer in 2023,the soil C∶P in each soil layer was also the lowest in T3,while the microbial biomass N∶P in the T1 treatment was the lowest among all fertilization treatments.Soil C∶N and C∶P increased with soil depth.Correlation analysis showed that organic carbon,total nitrogen,total phosphorus,available nitrogen,available phosphorus and microbial biomass carbon,nitrogen and phosphorus were significantly positively correlated with each other.In summary,the substitution of organic fertilizer for chemical fertilizer can not only change the soil nutrient and soil microbial biomass content,but also change the soil ecological stoichiometry characteristics,and the treatment with 50% organic fertilizer+50% chemical fertilizer has the best effect.

In order to research the influences of nitrogen reduction combined with soil conditioners on the growth and Cd uptake of rice to provide a scientific basis for Cd pollution paddy field used safely and fertilization reasonably.A field experiment was conducted to investigate the influences of nitrogen reduction combined with the alkaline slow-release fertilize,organic fertilizer and microbial fertilizer on the rice yields and Cd contents in the Cd contaminated paddy soil.The results showed that the rice yields increased by 7.42%(P<0.05), 8.59%(P<0.05) and 4.59% than the contrast with the application of alkaline slow-release fertilize, organic fertilizer and microbial fertilizer respectively. And the rice yields increased by 5.55% and 7.61%(P<0.05),respectively,of the nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer,but the nitrogen reduction 20% with microbial fertilizer decreased the production by 2.48%.So the results suggested that it was feasible to reduce the N fertilizer under this experiment condition.Both the alkaline slow-release fertilizer applied alone or combined with nitrogen reduction 20% could increase the soil pH effectively and decrease the soil available Cd content,and reduced the Cd contents of rice stem and grain efficiently with 31.29% (P<0.05) and 26.58% (P<0.05) than the contrast.Applying of organic fertilizer also increased the soil pH value and reduced the soil available Cd content effectively,and reduced the Cd contents of stem and rice obviously,but there was no evident effect of decreasing of Cd contents in stem and rice when organic fertilizer combined with nitrogen reduction 20%,the Cd content of rice lowered by 31.27%(P<0.05) and 11.96% compared to the contrast when applied organic fertilizer alone and with nitrogen reduction 20%.And the Cd contents of stem and rice had no significant differences compared to the contrast both applied microbial fertilizer alone and with nitrogen reduction 20%.The effect on decreasing Cd content of stem and rice weakened when nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer and microbial fertilizer.Overall consideration of the rice yields and the Cd reduction effects of rice and stem,nitrogen reduction 20% combined with alkaline slow-release fertilizer could enhance rice yield as well as reduce Cd content in rice stem and rice,which was applicable for rice production in Cd contaminated paddy soil.