Journal of Integrative Agriculture

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稻麦轮作下秸秆还田和夜间增温可提高冬小麦产量和氮素利用效率

  

  • 修回日期:2024-12-13

Straw returning and night-warming improve grain yield and nitrogen use efficiency of winter wheat under rice-wheat rotation

Pan Hou, Qiang Gao, Yingkai Ren, Jinhong Yu, Lijun Gao, Xiaoxue Liu, Dong Jiang, Weixing Cao, Tingbo Dai, Zhongwei Tian   

  1. Key Laboratory of Crop Physiology Ecology and Production Management of Ministry of Agriculture and Rural Affairs/College of Agriculture, Nanjing Agricultural University, Nanjing 210095, China

  • Revised:2024-12-13
  • About author:Pan Hou, E-mail: 2021201008@stu.njau.edu.cn; Correspondence Tingbo Dai, Tel: +86-25-84395033, E-mail: tingbod@njau.edu.cn; Zhongwei Tian, Tel: +86-25-84399623, E-mail: zhwtian@njau.edu.cn
  • Supported by:

    This study financially supported by the National Natural Science Foundation of China (32272215) and the Collaborative Innovation Center for Modern Crop Production by Province and Ministry (CIC-MCP), Nanjing Agricultural University, China.

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摘要：

全球气候变暖表现为夜间和冬春季的增温幅度大于白天和夏秋季节的非对称性特点，同时稻麦轮作下水稻秸秆还田是目前秸秆利用的主要方式。然而，秸秆还田和夜间增温互作对小麦产量和氮利用效率的影响尚不明确。因此，本研究通过连续三年的大田试验，设置两个秸秆处理（S0：秸秆离田；S1：秸秆还田）和两个增温处理（W0：不增温对照；W1：冬春季夜间增温）研究了小麦产量和氮利用的响应特征。研究结果表明，S1和W1均能提高小麦籽粒产量和氮利用效率，且W1的提高幅度更大。与S0W0相比，S1W1通过增加穗粒数和千粒重进一步提高了产量（13.0 %）和氮利用效率（16.5 %）。S1W1处理下植株将更多的氮向叶片分配且具有较高的氮代谢酶活性，提高了氮向籽粒的转运能力和花后干物质的积累。S1W1处理下拔节后土壤氮获取酶活性、有机氮矿化速率和微生物生物量氮升高使得土壤氮供应能力增强，有利于开花期根系生长，从而提高植株对氮素的吸收。S1W1处理下20-60 cm土层无机氮含量降低使得土壤-小麦系统表观氮盈余减少，氮损失降低。因此，秸秆还田、夜间增温及其互作通过提高表层土中的根系分布和土壤氮供应能力来增强植株氮吸收及其向籽粒的转运，从而提高了小麦的产量和氮利用效率。

Abstract:

Global climate warming is characterized by diurnal and seasonal asymmetry, with greater increases at nighttime and in winter and spring, and growing evidence has recognized that night-warming in winter and spring significantly impacts winter wheat production.  Pre-crop straw returning is the principal method for straw utilization currently and in the future, but the interactions between straw returning and night-warming on wheat yield and NUE (N use efficiency) still remain elusive.  Here, a consecutive three-year field experiment with two straw treatments (S0, straw removal; S1, straw returning) and two warming treatments (W0, no warming control; W1, night-warming) found that both S1 and W1 improved wheat grain yield and NUE, with W1 exhibiting more pronounced improvements.  Notably, the interaction between S1 and W1 (S1W1) further enhanced yield and NUE by 13.0 and 16.5% compared to S0W0 through increasing grain number and 1,000-grain weight, respectively (three-year average).  Additionally, root growth and topsoil inorganic N content exhibited reductions in S1 before jointing, thus reducing plant dry matter and N accumulation.  However, W1 exhibited an opposite trend, thereby mitigating these negative effects.  Simultaneously, under S1W1, increased N translocation to grain and post-anthesis dry matter accumulation, driven by greater N distribution to leaves and higher N metabolism enzyme activity, enhanced both yield and NUE.  This improvement was supported by better root morphology and biomass, particularly in the 0−40 cm soil layer, boosting plant N absorption.  Additionally, elevated soil N-acquiring enzyme activity after jointing increased the net N mineralization rate and microbial biomass N, enhancing soil N-supply capacity.  As a result, post-jointing inorganic N content rose in the 0−20 cm layer while decreasing at 20−60 cm, thus reducing the apparent N surplus.  Collectively, straw returning, night-warming, and their interactions enhanced more root distribution and N-supply capacity after jointing in the topsoil layer to increase plant N uptake and its translocation to grains, along with post-anthesis dry matter accumulation, ultimately improving grain yield and NUE.

Key words: wheat , straw returning , night-warming , nitrogen use efficiency , root growth , soil nitrogen-supply capacity