Modification of the existing cropping practice is needed to maintain rice (Oryza sativa L.) productivity and reduce irrigation water input. A 2-year field experiment was conducted during the dry rice growing season of 2016 and 2017 at the Asian Institute of Technology, Pathum Thani, Thailand, to investigate the effects of establishment method and irrigation level on growth, yield, and water productivity of irrigated lowland rice. The treatments consisted of two Thai rice cultivars (Pathumthani 1 and RD57), two establishment methods (dry direct seeding [DDS] and transplanting [TP]), and three irrigation levels (continuous flooding [CF], 15 cm threshold water level below the soil surface for irrigation [AWD15], and 30 cm threshold water level below the soil surface for irrigation [AWD30]). Overall, the performance of RD57 was better than Pathumthani 1 under DDS with 50% higher grain yield and 90% higher water productivity at AWD15. RD57 also had higher shoot dry matter, number of tiller m–2, and number of panicle m–2 across establishment methods and irrigation levels. Grain yield and water productivity of RD57 were similar under two establishment methods across irrigation levels, whereas the performance of TP was better than DDS for Pathumthani 1 irrespective of irrigation levels. The highest grain yield and water productivity of Pathumthani 1 was observed at AWD15 under TP and that of RD57 under both establishment methods at the same irrigation level. AWD15 saved 26 and 32% irrigation water under TP and DDS, respectively, compared with TP-CF treatment combination. AWD15 irrigation level could be recommended for greater water productivity without compromising yield when Pathumthani 1 is cultivated through TP and RD57 is cultivated through either DDS or TP. Although water-saving potential was higher compared with CF, AWD30 is not recommended for irrigated lowland rice cultivation due to significant yield reduction.

中文翻译：

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栽植方式和水分管理对热带低地水稻产量和水分生产力的影响

需要修改现有的种植方式以保持稻米（水稻L.) 生产力和减少灌溉水的投入。在泰国巴吞他尼的亚洲理工学院于 2016 年和 2017 年旱稻生长期进行了为期 2 年的田间试验，以研究建立方法和灌溉水平对灌溉水稻生长、产量和水分生产力的影响。低地水稻。处理包括两个泰国水稻品种（Pathumthani 1 和 RD57），两种种植方法（干直播 [DDS] 和移栽 [TP]），以及三个灌溉水平（连续泛滥 [CF]，低于 15 cm 的阈值水位）用于灌溉的土壤表面 [AWD15]，以及用于灌溉的土壤表面以下 30 厘米的阈值水位 [AWD30]）。总体而言，RD57 在 DDS 下的表现优于 Pathumthani 1，在 AWD15 下谷物产量提高了 50%，水分生产率提高了 90%。–2, 和穗数 m–2跨越建立方法和灌溉水平。RD57 的粮食产量和水分生产力在两种不同灌溉水平的建立方法下相似，而无论灌溉水平如何，对于 Pathumthani 1，TP 的表现都优于 DDS。Pathumthani 1 的产量和水分生产率在 TP 下的 AWD15 和 RD57 在相同灌溉水平的两种建立方法下观察到最高。与 TP-CF 处理组合相比，AWD15 在 TP 和 DDS 下分别节省了 26% 和 32% 的灌溉用水。当通过 TP 种植 Pathumthani 1 并且通过 DDS 或 TP 种植 RD57 时，可以推荐 AWD15 灌溉水平以提高水生产率而不影响产量。虽然节水潜力比CF更高，