Abstract It is still a long-term challenge to improve crop production and economic benefits in arid area of northwest China. The objective of this study was therefore to propose a new and promising cotton/mung bean intercropping (CMBI) system to cope with the challenge based on the traditional monocropping cotton (MC) system. A two-year field experiment was conducted to evaluate crop production and economic benefits between the CMBI and MC systems by analyzing the total land output (TLO), aboveground dry matter, nitrogen uptake, water use efficiency (WUE), nitrogen use efficiency (NUE), partial factor productivity (PFP) of nitrogen, and economic benefits. Experiment treatments consisted of two cropping systems (MC and CMBI systems) and a combination of the CMBI system with different N-fertilizer rates [160 (N160), 315 (N315), 390 (N390), and 475 (N475) kg ha−1 in 2016, and 160 (N160), 315 (N315), and 390 (N390) kg ha−1 in 2017], respectively. All treatments were designed using a randomized complete block with three replications. The results indicated that no significant differences in growth parameters [PH (plant height), SD (stem diameter), and LAI (leaf area index)] of cotton were found between the MC and CMBI systems in 2016 and 2017. Compared with the MC system, however, the CMBI system significantly increased TLO, aboveground dry matter, total N uptake, WUE, NUE, PFP for nitrogen, and economic benefits in 2016 and 2017. The result suggested the CMBI system had greater production advantages and economic benefits than the MC system. In addition, compared to the N160 treatment, other N treatments (N315, N390, and N475) in the CMBI system significantly enhanced crop growth, TLO, total aboveground dry matter, total N uptake, WUE, and economic benefits. However, PFP for nitrogen and NUE significantly decreased with the increase of application N rates. According to analyzing the production functions of different application N treatments, we found that 390 kg ha−1 in the CMBI system might be recommended as an appropriate application N rate to improve crop production and economic benefits in the arid area of northwest China.

中文翻译：

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棉花/绿豆间作提高西北干旱区作物生产力、水分利用效率、氮素吸收量和经济效益

摘要 提高西北干旱区农作物产量和经济效益仍是一项长期挑战。因此，本研究的目的是提出一种新的、有前景的棉花/绿豆间作 (CMBI) 系统，以应对基于传统单作棉花 (MC) 系统的挑战。通过分析土地总产量 (TLO)、地上干物质、氮吸收、水分利用效率 (WUE)、氮利用效率 (NUE)，进行了为期两年的田间试验，以评估 CMBI 和 MC 系统之间的作物产量和经济效益)、氮的部分要素生产率 (PFP​​) 和经济效益。试验处理包括两种种植系统（MC 和 CMBI 系统）以及 CMBI 系统与不同施氮量的组合 [160 (N160), 315 (N315), 390 (N390), 2016 年分别为 475 (N475) kg ha-1，2017 年分别为 160 (N160)、315 (N315) 和 390 (N390) kg ha-1]。所有治疗均使用随机完整区组设计，重复三次。结果表明，2016年和2017年MC和CMBI系统之间棉花的生长参数[PH（株高）、SD（茎直径）和LAI（叶面积指数）]没有显着差异。 与MC相比然而，CMBI 系统在 2016 年和 2017 年显着提高了 TLO、地上干物质、总氮吸收量、WUE、NUE、氮的 PFP 和经济效益。 结果表明 CMBI 系统比 CMBI 系统具有更大的生产优势和经济效益MC系统。此外，与 N160 处理相比，CMBI 系统中的其他 N 处理（N315、N390 和 N475）显着促进了作物生长、TLO、总地上干物质、总氮吸收量、WUE 和经济效益。然而，随着施氮量的增加，氮的 PFP 和 NUE 显着降低。通过分析不同施氮处理的生产函数，我们发现CMBI系统中390 kg ha-1可作为提高西北干旱区作物产量和经济效益的适宜施氮量。