Ridge-furrow plastic film mulching (RFM) planting system can conserve soil water and boost crop yield in semi-arid rainfed agricultural areas. In the east African Plateau (EAP), the RFM system has shown significant promoting effects on the yield and water use efficiency in maize (Zea mays L.) and wheat (Triticum aestivum L.). Although the RFM system is effective and efficient, it is unclear how to further increase crop productivity under RFM in EAP where soil moisture is limited. This study advocates for an integrated practice (maize straw returning) in the RFM system. Field trials were conducted using maize cultivar DK8031 to investigate the effects of maize straw returning in the shallow soil layer on soil hydrothermal conditions from 2021 to 2022. Maize productivity, water use efficiency, soil organic carbon, and soil total nitrogen were determined under RFM in Kenya, EAP. Three treatments were designed as follows: 1) conventional bare flat planting, CK; 2) RF with full plastic film mulching, RFM; and 3) RFM with maize straw piece (9 t ha−1) returning to 0–30 cm soil layer, RFMR. The results indicated that soil water storage (SWS) was substantially improved by 40.8 mm in 2021 and 30.9 mm in 2022 in RFMR, respectively, than that of CK, which was also significantly greater than that of RFM (p<0.05). Under relatively high air temperature at the silking stage, soil temperature at 15 cm soil depth was averagely reduced by 0.85 °C in RFMR and 0.15 °C in RFM, respectively, compared with CK. Across two growing seasons, grain yield and water use efficiency increased by 470 kg ha−1 and 1.5 kg ha−1mm−1 in RFMR compared to RFM and 2407 kg ha−1 and 7.1 kg ha−1mm−1 compared with CK, respectively., The highest economic benefit was found in RMFR, relative to RFM and CK. The above trend was positively associated with the improvements in hydrothermal conditions in the shallow soil layer. Additionally, soil organic carbon was increased by 0.88 g kg−1 in RFMR relative to CK due to improved soil structure and physiochemical traits. For the first time, we found that straw pieces returning to the shallow soil layer can further boost maize productivity on the basis of RFM, which was intended to improve soil texture in EAP.

中文翻译：

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秸秆掺入浅层土壤通过影响半干旱东非高原的土壤热液条件和玉米繁殖分配来提高田间生产力


垄沟塑料薄膜覆盖 （RFM） 种植系统可以保护土壤水分并提高半干旱雨养农业地区的作物产量。在东非高原 （EAP），RFM 系统对玉米 （Zea mays L.） 和小麦 （Triticum aestivum L.） 的产量和水分利用效率显示出显著的促进作用。尽管 RFM 系统有效且高效，但尚不清楚如何在土壤水分有限的 EAP 中进一步提高 RFM 下的作物生产力。本研究提倡在 RFM 系统中进行综合实践（玉米秸秆还田）。使用玉米品种 DK8031 进行田间试验，研究 2021 年至 2022 年玉米秸秆还田对浅层土壤热液条件的影响。玉米生产力、水分利用效率、土壤有机碳和土壤全氮在肯尼亚 RFM 下测定。设计了 3 个处理如下：1） 常规裸平种植，CK;2） 全膜覆盖射频，RFM;3） 玉米秸秆块 （9 t ha-1） 返回 0-30 cm 土层的 RFM，RFMR。结果表明，RFMR 土壤储水量 （SWS） 在 2021 年和 2022 年分别比 CK 显著提高了 40.8 mm 和 30.9 mm，也显著大于 RFM （p<0.05）。在吐丝期相对较高的空气温度下，RFMR 和 RFM 在 15 cm 土壤深度的土壤温度分别比 CK 平均降低了 0.85 °C 和 0.15 °C。在两个生长季节中，RFMR 的粮食产量和水分利用效率比 RFM 提高了 470 kg ha-1 和 1.5 kg ha-1mm-1，与 CK 相比增加了 2407 kg ha-1 和 7.1 kg ha-1mm-1， 分别，相对于 RFM 和 CK，RMFR 的经济效益最高。 上述趋势与浅层土壤热液条件的改善呈正相关。此外，由于土壤结构和理化特性的改善，RFMR 中的土壤有机碳相对于 CK 增加了 0.88 g kg-1。我们首次发现，秸秆块返回浅层土壤可以在RFM的基础上进一步提高玉米生产力，RFM旨在改善EAP的土壤质地。