Nan Cao , Guodong Chen , Shuang Wang , Huqiang Li , Jiao Lin , Qiang Hu , Sumei Wan
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引用次数: 0
Abstract
Context
Jujube (Zizyphus jujube Mill.) and cotton (Gossypium hirsutum L.), renowned for their drought and salt tolerance, form a resilient intercropping system in arid northwest China. While optimizing planting density and nitrogen (N) fertilization can enhance system productivity, their combined effects on greenhouse gas (GHG) emissions, carbon (C) sequestration and yield in such systems remain understudied. We hypothesize that strategic adjustments to plant density and N management could achieve sustainable yield while mitigating GHG emissions in the intercropping system.
Methods
A two-year field experiment evaluated three planting densities (D1: 14 × 104, D2: 18 × 104, D3: 22 × 104 plants ha−1) and three N application rates (N1: 140, N2: 280, N3: 420 kg N ha−1) to quantify impacts on yield, GHG emissions (CO2, N2O, CH4), soil C storage, and N use efficiency (NUE) in a jujube/cotton intercropping system.
Results
Increasing plant density and N rates elevated CO2 and N2O emissions by 37.8–69.4 % and 18.6–70.3 %, respectively, while diminishing CH4 uptake under higher N inputs. The D2N2 treatment (18 ×104 plants ha−1, 280 kg N ha−1) achieved the highest seedcotton yield, surpassing D3N2 (22 × 104 plants ha−1, 280 kg N ha−1) and D3N3 (22 × 10⁴ plants ha−1, 420 kg N ha−1) by 9.7 % and 11.2 %, respectively. This combination (D2N2) also minimized greenhouse gas intensity (GHGI) by 55.8–120.1 % and enhanced NUE by 48.3 % compared to D2N3. Soil organic C (SOC) storage increased by 13.5–23.8 % under D2N2, whereas excessive N application (N3) reduced soil inorganic C (SIC) by 9.6–17.7 %.
Conclusions
Optimizing plant density (18 × 10⁴ plants ha−1) and N fertilization (280 kg N ha−1) synergistically balances productivity, GHG mitigation, and soil C sequestration. These findings highlight the viability of tailored agronomic practices to achieve environmentally sustainable intercropping systems in arid regions, aligning with global climate resilience goals.
期刊介绍:
Field Crops Research is an international journal publishing scientific articles on:
√ experimental and modelling research at field, farm and landscape levels
on temperate and tropical crops and cropping systems,
with a focus on crop ecology and physiology, agronomy, and plant genetics and breeding.