摘要
稻田背景氮高是我国氮肥利用率低的主要原因之一,减少氮肥施用量对提高氮肥的农学利用率和缓解环境压力具有重要的意义。研究采用长期定位试验(19902006年)土壤全氮、稻谷产量等数据,分析施肥模式对稻田耕层土壤氮储量、氮肥农学利用率的影响,探讨在降低常规施用氮量的33.3%而不明显减产措施的可行性。结果表明:长期有机物质循环利用能显著提高耕层土壤全氮含量,氮储量与试验前相比平均提高了18.8%,仅施用化肥对土壤全氮含量没有显著影响,减量施肥处理(JS)对耕层土壤氮的积累效应一直优于仅施化肥的处理(NP、NPK)。17a的JS处理并没有降低稻谷产量,与常量NPK储量相比年际产量相对误差仅为3.2%,而输入N的农学利用率提高了12%。在半量稻草还田的条件下减少氮肥的施用量到180kg·hm-2是可行的,红壤稻田产量可维持在10t·hm-2左右。
High soil indigenous N supply of paddy soil is one of the major reasons of low fertilizer-N use efficiency.Reducing amount of N fertilizer annually can significantly improve fertilizer-N use efficiency and abate environmental stresses.In this study,by analyzing the data of soil total nitrogen and rice yield of long-term field experiment（from 1990 to 2006） in reddish paddy soil,the impact of different fertilizer regimes on soil N storage,N agronomic use efficiency（AUE） and the feasibility of reducing the amount of N fertilizer application by 33.3% were studied.Results showed that long-term cycling of organic matter（17 a） significantly increased soil total N storage in upper layer by 18.8%,while no obvious changes were detected from the plots only applying chemical fertilizers.In the treatment of chemical fertilizer reduction,the accumulation of soil nitrogen in plough layer was higher than that in NP and NPK treatments.Compared with NPK,chemical fertilizer reduction regime resulted in relative error of Grain yield of 3.2% and the increase of input-N AUE 12.0%.Therefore,the economical N fertilizer application under the recycling of half rice straw incorporation was 180 kg · hm-2 while rice yield could maintain about 10 t · hm-2.
出处
《生态学报》
CAS
CSCD
北大核心
2010年第18期5059-5065,共7页
Acta Ecologica Sinica
基金
国家重点基础研究发展计划资助项目(2005CB121106)
湖南省自然科学基金资助项目(08JJ3090)
中国科学院知识创新工程资助项目(KZCX2-YW-423
KZCX2-YW-Q1-07)
关键词
红壤稻田
施肥模式
表层土壤氮储量
节氮可行性
reddish paddy
fertilization systems
soil profile nitrogen storage
feasibility of reducing the amount of N fertilizer application
