AimsDrought is the major constraint to rainfed rice productivity in South Asia, but few reports provide detailed characterization of the soil properties related to drought stress severity in the region. The aim of the study was to provide a compilation of drought breeding network sites and their respective levels of drought stress, and to relate soil parameters with yield reduction by drought.MethodsThis study characterized levels of drought stress and soil nutrient and physical properties at 18 geographically distributed research station sites involved in rice varietal screening in Bangladesh, India, and Nepal, as well as at farmers’ fields located near the research stations.ResultsBased on soil resistance to penetration profiles, a hardpan was surprisingly absent at about half of the sites characterized. Significant relationships of depth of compaction and yield reduction by drought indicated the effects of soil puddling on susceptibility to cracking, rather than water retention by hardpans, on plant water availability in this region. The main difference between research stations and nearby farmers’ fields was in terms of soil compaction.ConclusionsThese results present an initiative for understanding the range of severities of reproductive-stage drought stress in drought-prone rainfed lowland rice-growing areas in South Asia.

中文翻译：

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在孟加拉国、印度和尼泊尔的品种筛选地点，土壤压实深度主要影响生育期干旱导致的水稻减产

目的 干旱是南亚旱作水稻生产力的主要制约因素，但很少有报告提供该地区与干旱胁迫严重程度相关的土壤特性的详细描述。该研究的目的是提供干旱繁殖网络站点及其各自干旱胁迫水平的汇编，并将土壤参数与干旱造成的减产联系起来。方法本研究表征了 18 个地理区域的干旱胁迫水平以及土壤养分和物理特性在孟加拉国、印度和尼泊尔以及位于研究站附近的农田中分布了参与水稻品种筛选的研究站站点。结果基于土壤对渗透剖面的抵抗力，在大约一半的特征站点中令人惊讶地没有硬质盘. 压实深度和干旱导致的产量减少之间的显着关系表明，土壤水坑对开裂敏感性的影响，而不是硬盘的保水性，对该地区植物水分的有效性。研究站和附近农田之间的主要区别在于土壤压实。结论这些结果为了解南亚易干旱雨养低地水稻种植区生殖阶段干旱胁迫的严重程度提供了一个倡议。