摘要： 为探明有机肥部分替代化肥对青东黄土高原土壤碳氮磷生态化学计量特征的影响,利用2022年建立的有机肥部分替代化肥马铃薯(青薯9号)连作田间定位试验,研究了有机肥部分替代化肥对青东黄土高原马铃薯农田土壤生态化学计量特征的影响,试验共设置不施肥(CK)、100%化肥(T1)、30%有机肥+70%化肥(T2)、50%有机肥+50%化肥(T3)、70%有机肥+30%化肥(T4)5个处理,测定土壤有机碳、全氮、全磷、碱解氮、速效磷和微生物量碳、氮、磷含量及土壤-微生物量生态化学计量学特征。结果表明,相比2022年,2023年各施肥处理的土壤有机碳、全氮、全磷、碱解氮、速效磷和微生物量碳、氮、磷含量均表现为增加趋势,而不施肥处理则呈降低趋势。不同土层间,各指标含量均随土层深度增加而逐渐降低。不同处理间,按各指标含量高低排序均为T3>T4>T2>T1>CK。在0~30 cm土层,T3处理下土壤有机碳、全氮、全磷、碱解氮、速效磷和微生物量碳、氮、磷含量比CK平均分别提高6.88%,17.65%,17.88%,84.71%,77.01%,65.67%,80.07%,54.91%。而各土层的土壤C∶N和C∶P均为CK处理最高。在4种施肥处理中,土壤C∶N、微生物量C∶N和C∶P均表现为T3处理最低;除2023年0~10 cm土层外,各土层土壤C∶P也表现为T3最低,而T1处理微生物量N∶P在所有施肥处理中最低。随土层加深土壤C∶N和C∶P呈升高趋势。相关性分析表明,有机碳、全氮、全磷、碱解氮、速效磷和微生物量碳、氮、磷相互之间均呈极显著正相关关系。综上,有机肥替代化肥不仅能够提高土壤养分和土壤微生物量含量,还能使土壤生态化学计量学特征产生改变,且以50%有机肥+50%化肥配施处理效果最好。

关键词: 有机肥部分替代化肥, 土壤, 微生物量, 生态化学计量学, 青东黄土高原

Abstract:

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.

Key words: Organic fertilizer partially replaces chemical fertilizer, Soil, Microbial biomass, Ecological stoichiometry, Qingdong Loess Plateau

中图分类号: 

• S158

• S963.91