Abstract. Drought is increasingly common due to frequent occurrences of extreme weather events, which further increases soil water repellency (SWR) and influences grain yield. Conservation agriculture is playing a vital role in attaining high food security and it could also increase SWR. However, the relationship between SWR and grain yield under conservation agriculture is still not fully understood. We studied the impact of SWR in 0–5 cm, 5–10 cm, and 10–20 cm layers during three growth periods on grain yield from a soil water availability perspective using a long-term field experiment. In particular, we assessed the effect of SWR on soil water content under two rainfall events with different rainfall intensities. Three treatments were conducted: conventional tillage (CT), reduced tillage (RT), and no-tillage (NT). The results showed that the water repellency index (RI) of NT and RT treatments in 0–20 cm layers was increased by 12.9 %–39.9 % and 5.7 %–18.2 % compared to CT treatment during the three growth periods, respectively. The effect of the RI on soil water content became more obvious with the decrease in soil moisture following rainfall, which was also influenced by rainfall intensity. The RI played a prominent role in increasing soil water storage during the three growth periods compared to the soil total porosity, penetration resistance, mean weight diameter, and organic carbon content. Furthermore, although the increment in the RI under NT treatment increased the soil water storage, grain yield was not influenced by RI (p > 0.05) because the grain yield under NT treatment was mainly driven by penetration resistance and least limiting water range (LLWR). The higher water sorptivity increased LLWR and water use efficiency, which further increased the grain yield under RT treatment. Overall, SWR, which was characterized by water sorptivity and RI, had the potential to influence grain yield by changing soil water availability (e.g. LLWR and soil water storage) and RT treatment was the most effective tillage management compared to CT and NT treatments in improving grain yield.

中文翻译：

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土壤拒水性通过改变长期耕作管理下的土壤水分可用性来影响玉米产量

摘要。由于极端天气事件的频繁发生，干旱变得越来越普遍，这进一步增加了土壤拒水性（SWR）并影响粮食产量。保护性农业在实现高度粮食安全方面发挥着至关重要的作用，它还可以增加 SWR。然而，保护性农业下SWR与粮食产量之间的关系仍不完全清楚。我们使用长期田间试验，从土壤水分有效性的角度研究了 0-5 cm、5-10 cm 和 10-20 cm 层的 SWR 在三个生育期对谷物产量的影响。特别是，我们评估了在不同降雨强度的两个降雨事件下 SWR 对土壤含水量的影响。进行了三种处理：常规耕作（CT）、减耕（RT）和免耕（NT）。结果表明，在三个生育期内，NT 和 RT 处理在 0-20 cm 层的防水指数（RI）分别比 CT 处理提高了 12.9%-39.9% 和 5.7%-18.2%。随着降雨后土壤水分的减少，RI对土壤含水量的影响更加明显，这也受降雨强度的影响。与土壤总孔隙度、渗透阻力、平均重量直径和有机碳含量相比，RI 在增加三个生长时期的土壤储水量方面发挥了突出作用。此外，虽然 NT 处理下 RI 的增加增加了土壤储水量，但粮食产量不受 RI 的影响（p > 0. 05) 因为 NT 处理下的谷物产量主要受穿透阻力和最小限水范围 (LLWR) 驱动。较高的吸水率提高了 LLWR 和水分利用效率，进一步提高了 RT 处理下的谷物产量。总体而言，以吸水性和 RI 为特征的 SWR 有可能通过改变土壤水分可用性（例如 LLWR 和土壤蓄水量）来影响粮食产量，并且与 CT 和 NT 处理相比，RT 处理是最有效的耕作管理。粮食产量。