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应用生态学报 ›› 2018, Vol. 29 ›› Issue (8): 2551-2558.doi: 10.13287/j.1001-9332.201808.026

• 研究报告 • 上一篇    下一篇

长期不同施氮量下冬小麦-夏玉米复种系统土壤硝态氮累积和淋洗特征

翁玲云, 杨晓卡, 吕敏娟, 辛思颖, 陈帅, 马文奇, 魏静*   

  1. 1河北农业大学资源与环境科学学院/河北省农田生态环境重点实验室, 河北保定 071000
  • 收稿日期:2016-10-21 出版日期:2018-08-20 发布日期:2018-08-20
  • 通讯作者: E-mail: weijing_199@163.com
  • 作者简介:翁玲云,女,1993年生,硕士研究生. 主要从事水土资源与环境生态研究. E-mail: 370802062@qq.com
  • 基金资助:

    本文由公益性行业(农业)科研专项(201103003)和国家重点基础研究发展计划项目(2015CB150405)资助

Characteristics of soil nitrate accumulation and leaching under different long-term nitrogen application rates in winter wheat and summer maize rotation system.

WENG Ling-yun, YANG Xiao-qia, LYU Min-juan, XIN Si-ying, CHEN Shuai, MA Wen-qi, WEI Jing*   

  1. College of Resources and Environmental Science/Hebei Province Key Laboratory for Farmland Eco-environment, Hebei Agricultural University, Baoding 071000, Hebei, China.
  • Received:2016-10-21 Online:2018-08-20 Published:2018-08-20
  • Supported by:

    This work was supported by the Public Welfare Industry (Agriculture) Research Project (201103003) and National Key Basic Research Development Plan of China (2015CB150405).

摘要: 冬小麦夏玉米是华北平原主要的粮食作物,其集约化的农业种植体系虽然普遍实现了粮食的高产,但氮肥常年大量施用会造成土壤深层硝态氮累积、淋洗等问题.本文以河北清苑冬小麦-夏玉米复种体系为研究对象,设置不同施氮量(N0、N100、N180、N255、N330,分别表示施氮0、100、180、255、330 kg·hm-2),于2010—2016年开展6个周期定位试验,研究不同施氮量对土壤硝态氮累积和淋洗的影响.结果表明: 在12季冬小麦和夏玉米收获期各处理产量存在显著差异,土壤硝态氮含量表现为冬小麦季累积、夏玉米季淋洗的特点,且90和180 cm土层硝态氮累积量均表现为 N330>N255>N180>N100>N0.从土壤剖面分布看,硝态氮可淋洗至990 cm的深层土壤中,且出现6个累积峰,同时土壤硝态氮累积峰随施氮量增加而下移,N330处理累积峰最深在840 cm处.从各土层累积量的分配看,5个处理0~90 cm硝态氮累积量占比在10%左右,大部分都在90 cm以下,不能被植物利用.可见,夏玉米季硝态氮淋洗严重,施氮量越高,土壤硝态氮残留量越大,向土壤深层淋洗量也越多,由此带来的对地下水的污染风险应该引起重视.从产量与硝态氮累积情况来看,N180为最优处理.

Abstract: Winter wheat and summer maize were the main crops in the North China Plain. While intensive farming system could generally achieve high yield, the perennial large amounts of nitrogen (N) fertilization application cause environmental problems including NO3--N accumulation and leaching at deep soil layer. Here, the effects of different N application rates on soil NO3--N accumulation and leaching in winter wheat-summer maize cropping system were investigated from 2010 to 2016 at Qingyuan County, Hebei Province, China. There were five treatments with N application rates at 0 (N0), 100 (N100), 180 (N180), 255 (N255) and 330 (N330) kg·hm-2. Results showed that crop yield and soil N status significantly varied among treatments for both wheat and maize after each harvest, respectively. Soil NO3--N were accumulated during winter wheat growing season and leached to deeper soil during summer maize growing season. Moreover, the soil NO3--N accumulation amount in the 90 to 180 cm soil profile decreased with the decreases of N inputs (N330 > N255 > N180 > N100 > N0). Soil NO3--N could be leached to 990 cm soil depth. There were six NO3--N accumulation peaks in the soil profile, with the peaks presenting at deeper soil profile with higher N fertilization rate. The deepest peak appeared at 840 cm soil depth with the N application rate of 330 kg·hm-2. From the distribution of NO3--N accumulation in the soil profile, only around 10% of total NO3--N was accumulated between 0-90 cm soil depth, while the rest accumulated below 90 cm, which could not be largely absorbed by plants. Therefore, NO3--N leaching during summer maize growing season was serious and it was greater with higher N fertilization rate which might lead to increased risk of underground water contamination. In terms of balanced crop yield and soil NO3--N accumulation, the rate of 180 kg·hm-2 would be the optimum one in areas with similar cultivation and environmental conditions to the present study.