中国农业科学 ›› 2018, Vol. 51 ›› Issue (7): 1283-1293.doi: 10.3864/j.issn.0578-1752.2018.07.006

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

水氮互作对冬油菜氮素吸收和土壤硝态氮分布的影响

谷晓博,李援农,黄鹏,杜娅丹,陈朋朋,方恒   

  1. 西北农林科技大学水利与建筑工程学院/旱区农业水土工程教育部重点实验室,陕西杨凌 712100
  • 收稿日期:2017-10-09 出版日期:2018-04-01 发布日期:2018-04-01
  • 通讯作者: 李援农,E-mail:liyuannong@163.com
  • 作者简介:谷晓博,E-mail:gxb123027@163.com
  • 基金资助:
    国家公益性行业(农业)科研专项(201503125,201503105)、国家高技术研究发展计划(863计划)项目(2011AA100504)

Effects of Irrigation and Nitrogen Coupling on Nitrogen Absorption and Soil Nitrate Content of Winter Oilseed Rape

GU XiaoBo, LI YuanNong, HUANG Peng, DU YaDan, CHEN PengPeng, FANG Heng   

  1. College of Water Resources and Architectural Engineering, Northwest A&F University/Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas of Ministry of Education, Yangling 712100, Shaanxi
  • Received:2017-10-09 Online:2018-04-01 Published:2018-04-01

摘要: 目的】针对西北地区冬油菜蕾薹期干旱频发,农民大量灌溉和施氮导致的环境问题,探究西北地区冬油菜蕾薹期适宜的灌溉量和施氮量。【方法】通过2年田间试验,研究分析蕾薹期不同灌溉量(不灌溉(I0)、灌60 mm(I1)和灌120 mm(I2))和施氮量(不施氮(N0)、施氮80 kg·hm-2N1)和施氮160 kg·hm-2N2))下,地上部干物质量、籽粒产量、氮素吸收与分配、土壤硝态氮分布和氮素利用效率的差异,其中全生育期不施氮(不基施、不追施)和不灌溉为对照处理(CK)。【结果】蕾薹期灌溉或施氮能显著提高冬油菜的地上部干物质量、籽粒产量、产油量和氮素吸收量。土壤硝态氮峰值所在的土层深度随灌水量的增加而明显下移,且峰值随施氮量的增加而明显增加,表现出明显的淋洗趋势。I1N1处理的土壤硝态氮累积量与I0N0处理间不存在显著差异,但与I2N2相比,却显著降低41.9 kg·hm-2I0、I1和I2处理土壤硝态氮主要分布在0—40、40—80和80—160 cm。2个冬油菜生长季,I2N1处理的籽粒产量和产油量均最大,平均为3 385和1 429 kg·hm-2CK最小,平均为1 391和585 kg·hm-2。与I2N1相比,2012—2013年(干旱年)I1N1处理的籽粒产量显著降低,但产油量无显著差异;2013—2014年(平水年)二者的籽粒产量和产油量均不存在显著差异。2年I1N1处理平均籽粒产量和产油量分别为3 264和1 358 kg·hm-2,仅比I2N1降低3.6%和4.7%。I1N1处理的平均氮肥农学利用率比I2N1降低7.2%。【结论】为提高冬油菜籽粒产量和氮素利用效率,减轻土壤硝态氮的下移趋势和下移量,I1N1处理(灌溉60 mm,施氮80 kg·hm-2)为较优的灌溉施氮策略。

关键词: 灌溉, 施氮, 蕾薹期, 产油量, 氮素吸收, 土壤硝态氮

Abstract: 【Objective】 This study aimed at the frequent drought at the stem elongation stage of winter oilseed rape (Brassica napus L.) in northwest China, and local farmers usually applied heavy irrigation and nitrogen (N) fertilizer for high benefits, thus led to serious environmental problems. The objective of present study was to determine the reasonable application amount of irrigation and N fertilizer at stem elongation stage of winter oilseed rape cultivated in northwest China. 【Method】 Ten treatments, including three nitrogen levels (N0: 0 kg·hm-2, N1: 80 kg·hm-2, N2: 160 kg·hm-2) and three irrigation levels (I0: 0 mm, I1: 60 mm, I2: 120 mm) at the beginning of stem elongation stage, and a control (CK) with no irrigation and no nitrogen (no basal nitrogen, no topdressing nitrogen) during the whole growing stage of winter oilseed rape were conducted in this two-year experiments. This study determined the effects of different irrigation and nitrogen levels on aboveground dry matter (ADM), seed yield, oil production, nitrogen uptake, soil nitrate content and nitrogen utilization efficiency of winter oilseed rape. 【Result】 Irrigation or nitrogen application at stem elongation stage significantly improved aboveground dry matter, seed yield, oil production and nitrogen accumulation amount of winter oilseed rape. The depth of soil layer with the peak of soil nitrate was moved down obviously with the increase of irrigation amount, and the peak value was increased with the increase of nitrogen application amount, which showed a clear trend of nitrate leaching with the increase of irrigation and nitrogen amount. Total soil nitrate-N accumulation amount in I1N1 was not significantly different with I0N0; however, was significantly decreased by 41.9 kg·hm-2 in comparison to I2N2. Soil nitrate-N was mainly distributed in 0-40, 40-80, and 80-160 cm soil layer. Seed yield varied from 1 534 to 3 024 kg·hm-2 and from 2 318 to 3 746 kg·hm-2 in 2012-2013 and 2013-2014, respectively. The highest seed yield and oil production were always occurred in I2N1, and the lowest were always occurred under CK for both seasons. Compared with I2N1, seed yield in I1N1 was significantly decreased in 2012-2013, a drought season, while no significant differences were found between I2N1 and I1N1 in 2013-2014, a wet season. No significant differences were found between I2N1 and I1N1 in both seasons. Average seed yield and oil production in I1N1 were 3 264 and 1 358 kg·hm-2 for both seasons, respectively, which were just 3.6% and 4.7% lower than I2N1, respectively. Nitrogen absorption amount in I1N1 was 7.3% significantly lower than in 2012-2013, while there were no marked differences between I1N1 and I2N1 in 2013-2014. Mean nitrogen agronomic efficiency in I1N1 was reduced by 7.2% in comparison with I2N1. 【Conclusion】 From the perspective of improving seed yield and nitrogen utilization efficiency of winter oilseed rape, and simultaneously alleviating the downward trend of soil nitrate, I1N1 (60 mm irrigation and 80 kg N·hm-2) treatment can be recommended as a suitable irrigation and nitrogen schedule for winter oilseed rape at stem elongation stage.

Key words: irrigation, nitrogen application, stem elongation stage, oil production, nitrogen absorption, soil nitrate nitrogen