Abstract Rice is predominantly grown on puddled soils (puddling is achieved through wet tillage in ponded water to create a soft soil environment and impermeable sub-soil layer) in the Eastern Gangetic Plains (EGP) of Bangladesh. Puddling is often discouraged while practicing conservation agriculture (CA) to achieve maximum system benefit. Zero-till unpuddled transplanted rice (ZT UPTR) could be a good substitute for puddled transplanted rice (PTR) as it possesses all the benefits to fit in a CA-based system. However, the performance of ZT UPTR might vary in different soil types and environments. The nitrogen (N) fertilizer management might also vary for different rice establishment methods and irrigation management. Therefore, two replicated field experiments were conducted in two diverse sites in the EGP, with significant variation in soil type and agro-climatic conditions. Three rice establishment methods – PTR, ZT UPTR, and rainfed ZT UPTR (ZT RUPTR) were compared in the main plots and three N rates (0, 45, and 90 kg ha−1, representing zero, half, and full recommended doses) were allocated in the sub-plots. We found that the recommended N management for both PTR and ZT UPTR was similar at both the sites, although the relative performance was different between the two different environments. In silt loam soil, the ZT UPTR performed equally or better than PTR (similar in the first season, a slight gain in grain yield in the second season). However, in sandy loam soil, the ZT UPTR performed slightly inferior to PTR (similar in the first season, lower grain yield in the second season). More water (about 564 mm) was required for growing ZT UPTR than PTR in the second season at the sandy loam site due to increased percolation rate in ZT UPTR caused by the cessation of puddling. Grain yield of ZT RUPTR was slightly lower (by 0.2 t ha−1) but statistically similar to PTR and ZT UPTR in both seasons in the silt loam soil, but significantly lower grain yield (by 1.5 t ha−1) in the first season and crop failure in the second season in the sandy loam soil. Therefore, ZT UPTR could be a feasible option in fine-textured soils for the establishment of rice in a CA-based system while its feasibility for coarse-textured soils seems limited and requires further study.

中文翻译：

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有水坑的和零耕没有水坑的移栽水稻各自最适合不同的环境——来自孟加拉国东部恒河平原两个不同地点的例子

摘要 水稻主要生长在孟加拉东部恒河平原 (EGP) 的水坑土壤上（水坑是通过在池塘水中湿耕来创造柔软的土壤环境和不透水的底土层）。在实践保护性农业 (CA) 以实现最大系统效益时，通常不鼓励混泥土。零浇灌移栽水稻 (ZT UPTR) 可能是浇灌移栽水稻 (PTR) 的良好替代品，因为它具有适合基于 CA 的系统的所有优点。然而，ZT UPTR 的性能在不同的土壤类型和环境中可能会有所不同。氮（N）肥管理也可能因不同的水稻种植方法和灌溉管理而异。因此，在 EGP 的两个不同地点进行了两次重复的田间试验，土壤类型和农业气候条件的显着变化。三种水稻建立方法——PTR、ZT UPTR 和雨育 ZT UPTR (ZT RUPTR) 在主要地块和三种 N 比率（0、45 和 90 kg ha-1，代表零、半和全推荐剂量）中进行了比较被分配在子地块中。我们发现 PTR 和 ZT UPTR 的推荐 N 管理在两个站点上是相似的，尽管两个不同环境之间的相对性能不同。在粉砂壤土中，ZT UPTR 的表现与 PTR 相当或更好（第一季类似，第二季粮食产量略有增加）。但在砂壤土中，ZT UPTR 的表现略逊于 PTR（第一季类似，第二季粮食产量较低）。由于停止搅动导致 ZT UPTR 中的渗透率增加，在沙壤土场地的第二季中，ZT UPTR 的生长需要比 PTR 更多的水（约 564 毫米）。ZT RUPTR 的粮食产量略低（0.2 t ha−1），但在粉砂壤土的两个季节中与 PTR 和 ZT UPTR 在统计上相似，但第一季的粮食产量显着降低（减少 1.5 t ha−1）砂壤土第二季歉收。因此，ZT UPTR 在细质地土壤中可能是一种可行的选择，用于在基于 CA 的系统中建立水稻，而其在粗质地土壤中的可行性似乎有限，需要进一步研究。2 t ha−1)，但在粉砂壤土中两个季节的 PTR 和 ZT UPTR 在统计上相似，但第一季的谷物产量显着降低（1.5 t ha−1），而沙质土壤中的第二季作物歉收壤土。因此，ZT UPTR 在细质地土壤中可能是一种可行的选择，用于在基于 CA 的系统中建立水稻，而其在粗质地土壤中的可行性似乎有限，需要进一步研究。2 t ha−1)，但在粉砂壤土中两个季节的 PTR 和 ZT UPTR 在统计上相似，但第一季的谷物产量显着降低（1.5 t ha−1），而沙质土壤中的第二季作物歉收壤土。因此，ZT UPTR 在细质地土壤中可能是一种可行的选择，用于在基于 CA 的系统中建立水稻，而其在粗质地土壤中的可行性似乎有限，需要进一步研究。