Direct-seeded rice (DSR) is a potent option for north-west India considering the current shortages of labour and water. The formation of a subsurface compact layer in medium to coarse textured soils due to continuous puddling used for commonly grown puddled, transplanted rice hampers the root growth of DSR and wheat crops. It is thus imperative to study the deep tillage effects on water balance and water productivity of the DSR–wheat cropping system. A two-year field experiment was conducted during 2016–17 and 2017–18 in a sandy loam soil to study the soil water dynamics in relation to tillage and irrigation regimes in a DSR–wheat cropping system. There were two irrigation regimes both in DSR (irrigation at 4-day and 8-day intervals) and wheat (based on irrigation water to pan evaporation ratio of 1.0 (I1.0) and 0.5 (I0.5)) in main plots; with three tillage treatments in subplots: (1) conventional tillage for both DSR and wheat (DSRCT-WCT), (2) deep tillage before sowing of DSR during the first season + conventional tillage in wheat (DSRDT1-WCT) and (3) deep tillage before sowing of DSR during both seasons + conventional tillage in wheat (DSRDT2-WCT). The irrigation water input was lower by 325 mm under 8-day, I0.5 compared with 4-day, I1.0 irrigation regimes during both years. The evapotranspiration (ET) was significantly higher in plots with the 4-day compared to 8-day irrigation regime by 22.8% and 17.2% during 2016 and 2017 respectively. In wheat, ET was significantly higher in plots with I1.0 than I0.5 by 42.7% and 34.8% during 2016–17 and 2017–18 respectively. The ET was significantly higher in DSRDT2-WCT and DSRDT1-WCT than DSRCT-WCT in DSR. The water productivity was higher in less frequently (8-day and I0.5) than in frequently irrigated (4-day and I1.0) plots. Deep tillage during both seasons (DSRDT2-WCT) had no significant influence on the soil water balance components and water productivity in comparison to deep tillage only once in two years (DSRDT1-WCT). However, the ET and water productivity were significantly higher in plots with deep tillage compared to conventional tillage.

中文翻译：

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深耕灌溉对印度西北部稻麦直播系统土壤水平衡和水分生产力的影响

考虑到目前劳动力和水的短缺，直播水稻 (DSR) 是印度西北部的一个有效选择。由于用于通常种植的泥浆、移栽水稻的连续泥浆，在中等至粗糙质地的土壤中形成地下致密层，阻碍了 DSR 和小麦作物的根系生长。因此，研究深耕对 DSR-小麦种植系统的水平衡和水分生产力的影响势在必行。2016-17 年和 2017-18 年在沙壤土中进行了为期两年的田间试验，以研究与 DSR-小麦种植系统中耕作和灌溉制度相关的土壤水分动态。主要地块的 DSR（4 天和 8 天间隔灌溉）和小麦（基于灌溉水与盘的蒸发比为 1.0（I1.0）和 0.5（I0.5））有两种灌溉方式；在子地块中进行三种耕作处理：（1）DSR 和小麦的常规耕作（DSRCT-WCT），（2）第一季 DSR 播种前深耕+小麦常规耕作（DSRDT1-WCT）和（3）两季 DSR 播种前深耕 + 小麦常规耕作 (DSRDT2-WCT)。与 4 天、I1.0 灌溉制度相比，8 天、I0.5 灌溉制度下的灌溉水输入在这两年中都降低了 325 毫米。2016 年和 2017 年，与 8 天灌溉制度相比，4 天灌溉地块的蒸散量 (ET) 分别高出 22.8% 和 17.2%。在小麦中，2016-17 年和 2017-18 年期间，I1.0 比 I0.5 的样地 ET 分别显着高 42.7% 和 34.8%。DSRDT2-WCT 和 DSRDT1-WCT 中的 ET 显着高于 DSR 中的 DSRCT-WCT。不经常灌溉（8 天和 I0.5）的水生产力高于经常灌溉（4 天和 I1.0）地块。与两年一次的深耕（DSRDT1-WCT）相比，两个季节的深耕（DSRDT2-WCT）对土壤水平衡成分和水分生产力没有显着影响。然而，与常规耕作相比，深耕地块的 ET 和水分生产力显着更高。