Journal of Integrative Agriculture ›› 2026, Vol. 25 ›› Issue (1): 326-338.DOI: 10.1016/j.jia.2025.04.029

• • 上一篇    下一篇

绿洲灌区间作绿肥结合化学氮肥减量通过优化团聚体组成提高土壤碳储量

  

  • 收稿日期:2024-12-13 修回日期:2025-04-25 接受日期:2025-03-24 出版日期:2026-01-20 发布日期:2025-12-09

Intercropping grain crops with green manure under reduced chemical nitrogen improves the soil carbon stocks by optimizing aggregates in an oasis irrigation area

Xiaohui Xu1, 2, Qiang Chai2#, Falong Hu1, 2, Wen Yin1, 2, Zhilong Fan1, 2, Hanting Li1, 3, Zhipeng Liu1, 2, Qiming Wang1, 2   

  1. 1 State Key Laboratory of Aridland Crop Science, Lanzhou 730070, China

    2 College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China

    3 College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, China

  • Received:2024-12-13 Revised:2025-04-25 Accepted:2025-03-24 Online:2026-01-20 Published:2025-12-09
  • About author:Xiaohui Xu, E-mail: xuxiaohui0318@126.com; #Correspondence Qiang Chai, E-mail: chaiq@gsau.edu.cn
  • Supported by:
    This work was supported by the National Key Research and Development Program of China (2021YFD1700204), the National Natural Science Foundation of China (U21A20218 and 32372238), the Modern Agro-Industry Technology Research System of China (CARS-22-G-12) and the “Innovation Star” Program of Graduate Students in 2025 of Gansu Province, China (2025CXZX-749).

PDF

摘要：

提高土壤有机碳(SOC)储量是实现农业可持续发展的重要途径。然而，在农业生产中, 使用豆科绿肥作物替代部分化学氮肥能否实现这一目标, 尚不明确。本研究通过为期六年的田间定位试验，探究绿肥间作结合化学氮肥减量对土壤有机碳储量的影响及土壤团聚体组成与碳固存之间的关系。试验采用裂区设计，主区设置三种种植模式：玉米间作箭筈豌豆(M/V)、玉米间作油菜(M/R)以及单作玉米(M), 在副区设置两种施氮梯度：常规施氮量(N2, 360 kg ha-1)和减量施氮(N1, 270 kg ha-1, 减少25%)。基于2020-2022年连续采集土壤样本。获得结果显示, 与单作玉米相比, 绿肥间作(M/V和M/R)显著提升了SOC含量, 三年平均增幅达12.1和9.1%，有效弥补了因施氮量减少25%所产生的负面影响。M/V与M/R之间无显著差异。在单作玉米中, N1条件下的SOC含量较N2处理降低了9.3-10.5%；但在间作绿肥模式(M/V和M/R)下, N1和N2处理的SOC储量差异并不显著。在N1处理下, M/V和M/R的土壤有机碳含量分别比单作玉米高20.9和16.3%, 而在N2处理下, 二者与单作玉米无差异。随着种植年限的延长，间作绿肥模式表现出显著的累积效应影响, 2022年这两种间作系统在0-20 cm土层的SOC含量相较于2020年提高了5.3%。减氮条件下, 间作绿肥与单作玉米相比, 增加了大团聚体(>0.25 mm)的比例及团聚体稳定性(MWD和GMD), 同时降低了微团聚体(<0.25 mm)的比例。结构方程模型表明，种植模式和施氮水平主要是是通过调控大团聚体组成和团聚体有机碳（AOC）间接影响SOC。相关性分析进一步揭示大团聚体组成与SOC含量呈显著正相关 (R2=0.64)。此外, 间作绿肥及减量施氮能够通过增加土壤有机碳含量维持较高的作物产量。本研究证实, 在绿洲灌溉区实施间作绿肥结合化学氮肥减量25%是优化土壤团聚体组成增加土壤有机碳汇、提高玉米产量的可行措施。

Abstract:

Enhancing soil organic carbon (SOC) stocks is a key aspect of modern agriculture, but whether this can be achieved by incorporating legume green manure crops in cereal production to substitute synthetic N fertilizers is unknown.  This study used a six-year (2017–2022) field study to explore the impacts of intercropping green manure with maize and reducing nitrogen fertilization on SOC stocks, while specifically focusing on the relationship between aggregate composition and carbon sequestration.  Maize intercropped with common vetch (M/V), maize intercropped with rapeseed (M/R), and sole maize (M), were each tested at conventional (N2, 360 kg ha–1) and reduced (N1, 270 kg ha–1, 25% reduced) N application rates.  Soil was sampled in 2020, 2021, and 2022.  Compared with sole maize, intercropping with green manure (M/V and M/R) significantly increased SOC stocks which compensated for any negative effect due to the 25% reduction in N application.  Based on 3-year averages, intercropping with M/V and M/R increased the SOC content compared to sole maize (M) by 12.1 and 9.1%, respectively, with intercropping further mitigating the negative impact of reduced nitrogen application.  There was no significant difference between M/V and M/R.  The SOC content at N1 was reduced by 9.3–10.5% compared to that at N2 in sole maize, but the differences in SOC stocks between N1 and N2 were not significant in the intercropping patterns (M/V and M/R).  The intercropped M/V and M/R showed 20.9 and 16.3% higher SOC contents compared to sole maize at N1, with no differences at N2.  Intercropping green manure led to a 5.3% greater SOC in the 0–20 cm depth soil in 2022 compared to that in 2020, due to the cumulative effect of two years of green manure intercropping.  Intercropping green manure (M/V and M/R) increased the proportion of macroaggregates (>0.25 mm) and aggregate stability while reducing the proportion of microaggregates compared to sole maize under the N1 application.  Structural equation modeling indicated that cropping patterns and nitrogen application levels mainly affect SOC indirectly by regulating the composition of macroaggregates and aggregate organic carbon (AOC).  Correlation analysis further revealed that the composition of macroaggregates is significantly and positively correlated with the SOC content (R²=0.64).  In addition, intercropping green manure can maintain high crop yields by increasing SOC under reduced chemical nitrogen application.  The results of this study show that intercropping green manure with grain crops can be a viable measure for increasing SOC sinks and maize productivity by optimizing the aggregate composition with reduced N application in the Hexi Oasis Irrigation Area.

Key words: intercropping green manure , soil organic carbon , soil aggregate composition , maize