Irrigation of rice using groundwater is considered one of the main contributors to north-west India's declining water level. The present study hypothesizes that zero-till direct seeding of rice (ZTDSR) with the optimum irrigation schedule may reduce irrigation compared to puddled transplanted rice (PTR). Crop growth stage-dependent predefined soil matric potential (SMP), that is, −15, −30 and −45 kPa based irrigation schedules either during the entire growing period or their combinations during the vegetative phase in ZTDSR, were compared with PTR for two consecutive seasons. The results showed that irrigation in ZTDSR at lower SMP at any growth stage caused adverse effects on yield. Irrigation at −15 kPa during the entire crop season with straw mulch was found to be the best schedule for ZTDSR. ZTDSR with −15 kPa irrigation, however, saved 36.2 cm of water and recorded higher water productivity but produced 20% less grain yield over the prevailing PTR. A higher groundwater system loss (GWSL) was found in the PTR (29.2 cm) than in the best ZTDSR (23.6 cm) schedule, which indicates better groundwater management in the ZTDSR than in the PTR. Hence, the ZTDSR has the potential to save irrigation, achieve higher water productivity and manage the depletion of groundwater resources in rice–wheat dominant north-west India.

中文翻译：

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与印度西北部地下水灌溉系统下的传统水稻泥坑移栽相比，评估不同水分胁迫水平下的零耕直接播种

使用地下水灌溉水稻被认为是印度西北部水位下降的主要原因之一。本研究假设，与泥播水稻（PTR）相比，具有最佳灌溉计划的水稻零耕直播（ZTDSR）可能会减少灌溉量。与作物生长阶段相关的预定义土壤基质势 (SMP)，即在整个生长期或其在 ZTDSR 营养阶段的组合中基于 -15、-30 和 -45 kPa 的灌溉计划，与两种方法的 PTR 进行了比较连续几个赛季。结果表明，在任何生长阶段，以较低的SMP进行ZTDSR灌溉都会对产量产生不利影响。整个作物季节使用秸秆覆盖物进行 -15 kPa 的灌溉被认为是 ZTDSR 的最佳方案。然而，采用 −15 kPa 灌溉的 ZTDSR 节省了 36.2 厘米的水，并记录了更高的水生产率，但与现行 PTR 相比，谷物产量减少了 20%。 PTR (29.2 cm) 中的地下水系统损失 (GWSL) 高于最佳 ZTDSR (23.6 cm) 方案，这表明 ZTDSR 中的地下水管理优于 PTR。因此，ZTDSR 有潜力节省灌溉、实现更高的水生产率并管理以水稻和小麦为主的印度西北部地下水资源的枯竭。