[目的]研究有机无机氮肥配比对南方稻麦轮作体系中水稻产量、氮素吸收利用的影响，以期为实现水旱轮作体系中水稻的高产高效和有机无机肥料的科学配施提供理论基础和科学依据。[方法]依托水稻-冬小麦轮作体系，以常规施氮量(225 kgNhm-2)为基准，在水稻季设置不施肥(CK)、100％化肥氮(CF)、75％化肥氮+25％有机肥氮(25％M)、50％化肥氮+50％有机肥氮(50％M)、25％化肥氮+75％有机肥氮(75％M)以及100％有机肥氮(100％M)6个处理，在第7个轮作周期水稻季分析水稻产量、氮素吸收量、氮素利用效率、氮平衡以及土壤碳氮含量的变化。[结果]相比对照处理，施肥处理提高了水稻的产量和吸氮量。水稻产量和籽粒吸氮量均随着有机肥占比的增加而呈先上升后下降的趋势。25％M处理下水稻产量和吸氮量最高，但与CF处理无显著差异。施肥处理的水稻氮素表观利用率变化范围在29。4％～50。0％之间，偏生产力范围为51。5～57。1 kg kg-1之间，其中以25％M处理下氮素效率最高。相比对照处理，不同施肥处理均降低氮素内部利用率，但不同施肥处理之间无显著差异。与对照相比，CF处理降低了土壤pH，而有机无机肥配施条件下的土壤pH高于CF处理。在不同有机无机肥配施的处理中，提高有机肥占比能显著提高土壤全碳、全氮和无机氮含量。根据灰色关联分析，与稻米产量关联度从高到低的土壤因子依次为:铵态氮、全碳、全氮、硝态氮、pH。[结论]在常规施氮量的条件下，与单施化肥相比，施氮比例为25％有机肥+75％无机肥的配施方案，能够保证水稻籽粒产量、吸氮量和氮素利用效率不下降的前提下，提升土壤碳氮含量和缓解土壤酸化效应。因此，基于南方稻麦轮作体系长期试验的结果，有机无机肥配施处理，相较于纯化肥处理，具有更大的产量优势和减肥潜力。
Effects of Long-term Combined Application of Organic-Inorganic Fertilizers on Rice Yield,Nitrogen Uptake and Utilization in a Rice-Wheat Rotation System
[Objective]The study investigated the effects of long-term combined application of organic and inorganic nitrogen(N)on rice yield,N uptake and utilization,pH,and soil carbon(C)and N content in the rice-wheat rotation system in southern China,which aimed to provide theoretical basis and scientific basis for improving rice yield and nutrient utilization efficiency as well as scientific application of organic and inorganic fertilizers.[Methods]Relying on the rice-winter wheat rotation system,based on the conventional nitrogen application amount(225 kg N hm-2),six treatments were set in the rice season,including no fertilizer(CK),100％fertilizer nitrogen(CF),75％fertilizer nitrogen+25％organic fertilizer nitrogen(25％M),50％fertilizer nitrogen+50％organic fertilizer nitrogen(50％M),25％fertilizer nitrogen+75％organic fertilizer nitrogen(75％M)and 100％organic fertilizer nitrogen(100％M).The rice yield,nitrogen uptake,nitrogen use efficiency,nitrogen balance,and soil carbon and nitrogen content were analyzed in the rice season of 7th rotation cycle.[Result]Compared with the CK treatment,the yield and N uptake of rice were increased under the different fertilization treatments.With the increase in the proportion of organic fertilizer,the rice yield and N uptake showed a trend of first increasing and then decreasing.25％M treatment had the highest rice yield and N uptake.Under fertilization treatments,the N recovery efficiencies were 29.4～50.0％;the N partial factor productivities were 51.5～57.1 kg kg-1.Among all treatments,25％M treatment had the highest N efficiency.Compared with CK treatment,different fertilization applications significantly reduced the internal N utilization rate,but there was no significant difference among the different fertilization treatments.Compared with the control,CF treatment decreased soil pH,while soil pH was increased in all amounts combined application of organic and inorganic fertilizer treatment(cf.CF treatment).The contents of total C,total N,and inorganic N in soil were increased with the proportion of organic fertilizer.According to grey correlation analysis,soil factors from high to low correlation with rice yield were ammonium N,total C,total N,nitrate N and pH.[Conclusion]Under the condition of conventional N application amount,compared with inorganic fertilizer application,the measurement of 25％organic fertilizer+75％inorganic fertilizer could increase soil C and N content and alleviate soil acidification on the promise that the grain yield,N uptake and N use efficiency of rice did not decrease.Therefore,from the perspective production of a rice-wheat rotation system in southern China,organic and inorganic combined application has greater advantages and potential in yield and fertilizer reduction than pure inorganic fertilizer treatment.
Organic fertilizer substitutionRice yieldRice N uptakeN efficiencySoil nutrient
NETL
NSTL
万方数据
