中国农业科学 ›› 2018, Vol. 51 ›› Issue (12): 2336-2347.doi: 10.3864/j.issn.0578-1752.2018.12.010

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

长期增施有机肥/秸秆还田对土壤氮素淋失风险的影响

盖霞普1,刘宏斌1,翟丽梅1,杨波1,任天志2,王洪媛1,武淑霞1,雷秋良1   

  1. 1中国农业科学院农业资源与农业区划研究所/农业部面源污染控制重点实验室,北京 100081;2中国农业科学院,北京 100081
  • 收稿日期:2017-08-21 出版日期:2018-06-16 发布日期:2018-06-16
  • 通讯作者: 王洪媛,Tel:010-82106737;E-mail:wanghongyuan@caas.cn
  • 作者简介:盖霞普,E-mail:happygaixiapu@126.com
  • 基金资助:
    国家重点研发计划项目(2016YFD0800101)

Effects of Long-Term Additional Application of Organic Manure or Straw Incorporation on Soil Nitrogen Leaching Risk

GAI XiaPu 1, LIU HongBin 1, ZHAI LiMei 1, YANG Bo 1, REN TianZhi 2WANG HongYuan 1, WU ShuXia 1, LEI QiuLiang 1   

  1. 1Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences/Key Laboratory of Nonpoint Source Pollution Control, Ministry of Agriculture, Beijing 100081; 2 Chinese Academy of Agricultural Sciences, Beijing 100081
  • Received:2017-08-21 Online:2018-06-16 Published:2018-06-16

摘要: 【目的】研究长期增施有机肥/秸秆还田对作物产量及土壤氮素淋失风险的影响,旨在为华北平原冬小麦-夏玉米轮作区增强土壤肥力、提高作物产量及降低农业面源污染风险提供依据。【方法】以国家褐潮土肥力与肥料效益监测基地的长期肥料试验为平台,研究长达27年不同施肥处理对冬小麦-夏玉米产量、土壤肥力、氮素淋失风险和土壤氮素剖面分布的影响,试验共设置5个施肥处理,即:对照(CK);氮磷钾(NPK);氮磷钾+有机肥(NPKM);氮磷钾+过量有机肥(NPKM+);氮磷钾+秸秆还田(NPKS)。【结果】(1)在27年的不同施肥处理中,长期增施有机肥/秸秆还田均能使作物增产,改善土壤肥力。其中,增施有机肥处理尤为显著,与NPK相比,NPKM、NPKM+处理提高小麦和玉米产量分别为41%—50%和30%—32%;增加0—20 cm表层土壤有机碳(SOC)和全氮(TN)含量分别为62%—121%、107%—187%;但降低小麦、玉米氮肥偏生产力(PFPN)分别达22%—32%、27%—41%。而NPKS处理对作物增产及提升土壤肥力的作用低于增施有机肥处理,对小麦产量、玉米产量、SOC、TN含量的增幅分别为24%、6%、9%、97%,但提高小麦季PFPN为216%、降低玉米季PFPN为40%。(2)长期增施有机肥/秸秆还田处理中,0—20 cm表层土壤SOC、TN、硝态氮(NO3-N)、可溶性碳氮等养分含量以及氮矿化速率、硝化潜势等微生物学过程显著高于20—200 cm,说明长期增施有机肥/秸秆还田等外源碳的添加对土壤养分及微生物学过程的影响主要发生在表层。(3)与NPK相比,NPKM处理能够显著增加100—200 cm深层土壤中NO3--N含量,NO3--N平均含量为17.8—26.1 mg·kg-1;而NPKS处理在一定程度上能够增加0—100 cm土层NO3--N含量,NO3--N平均含量为3.6—13.4 mg·kg-1,表明增施有机肥会促进土壤NO3--N的向下迁移,而秸秆还田对土壤NO3--N具有一定的固持作用。此外,由于有机肥和秸秆带入的氮素, NPKM、NPKM+、NPKS处理氮盈余比NPK处理增加312%、1 037%、953%,大大增加了土壤氮素淋失风险。【结论】在氮磷钾化肥基础上增施有机肥/秸秆还田会提高作物产量、增强土壤肥力,但会提高土壤氮盈余量,提高氮素淋失风险,尤其是增施有机肥会大大增加氮素淋失风险。

关键词: 长期施肥, 有机肥, 秸秆还田, 作物产量, 氮素淋失风险, 褐潮土, 冬小麦, 夏玉米

Abstract: 【Objective】In order to provide a basis for promoting soil fertility, increasing crop yield and reducing non-point source pollution for rotation of winter wheat and summer maize in North China Plain, it is necessary to study the effects of long-term additional application of organic manure/straw incorporation on crop yield and soil nitrogen leaching risk.【Method】Considering a 27-year long-term fertilizer experiment in Fluvo-aquic soil in Changping County, Beijing, China as the research platform, five treatments were set up, including namely control (CK), chemical fertilizers (NPK), NPK + organic manure (NPKM), NPK+ 50% more organic manure (NPKM+) and NPK + straw incorporation (NPKS). And then, crop yield of wheat and maize, soil fertility, nitrogen leaching risk and soil nitrogen distribution characteristics under different fertilization treatments were analyzed. 【Result】Results showed that (1) long-term additional application of organic manure or straw incorporation could increase crop yield and improve soil fertility during the past 27-year. Among these different fertilizer treatments, additional application of organic manure was particularly excellent. Compared with NPK, the yield of wheat and maize could increase by 41%-50% and 30%-32% under NPKM and NPKM+ treatments, respectively. Meanwhile, NPKM and NPKM+ treatments could increase soil organic carbon (SOC) and total nitrogen (TN) in 0-20 cm soil by 62%-121% and 107%-187%, respectively. However, the partial factor productivity (PFPN) in wheat and maize season was reduced by 22%-32% and 27%-41%, respectively. Contrarily, the effects of straw incorporation on yield enhancement and soil nutrients improvement was lower than that of additional application of organic manure. The yield of wheat and maize and SOC and TN contents were increased by 24%, 6%, 9%, 97% under straw returning, respectively, relative to NPK. However, the PFPN in wheat season was increased by 216% while was reduced by 40% in maize season. (2) SOC, TN, nitrate nitrogen (NO3--N), soil dissolved organic carbon, soil dissolved organic nitrogen contents and the microbiological processes of soil nitrogen mineralization rate and nitrification potential in 0-20 cm soil depth were all higher than that of 20-200 cm soil depth, which indicated that the effects of long-term additional application of organic manure or straw incorporation on soil nutrients and microbiological processes mainly occurred in the surface soil. Compared with NPK, NPKM treatment could significantly increase NO3--N content in the 100-200 cm soil layer and the average value of NO3--N was 17.8-26.1 mg·kg-1. NPKS treatment could increase soil NO3--N content in the 0-100 cm soil depth to some extent and the average content of NO3--N was 3.6-13.4 mg·kg-1. This indicated that additional application of organic manure could promote the downward migration of soil NO3--N and straw returning could retain soil NO3--N. As introducing additional nitrogen from manure or straw, the nitrogen surplus was increased by 312%, 1 037%, 953% in NPKM, NPKM+, NPKS treatments compared with NPK treatment, suggesting a relatively high nitrogen leaching risk.【Conclusion】Based on the conventional fertilization, long-term additional application of organic manure and straw incorporation could increase crop yield and soil fertility, but also promote soil nitrogen surplus and nitrogen leaching risk. Especially, long-term additional application organic manure could increase nitrogen leaching risk.

Key words: long-term fertilization, organic manure, straw incorporation, crop yield, nitrogen leaching risk, fluvo-aquic soil, winter wheat, summer maize