Abstract Two sets of field experiments under seedling transplanting and drill row seed planting methods were conducted side by side for two years during the main cropping seasons of 2017 and 2018 in Fogera Plain of northwest Ethiopia to study the effect of different sources, application methods and time of nitrogen fertilizer on growth and yield of rain-fed lowland rice. Three N sources of fertilizers (conventional Urea, Urea super-granule, and slow-release Urea) with six, one, and three application methods and times, respectively were laid out in a randomized complete block design (RCBD) in three replicates. These treatments and design were equally applied for two sets of experiments under both planting methods. Results revealed that soil-plant analysis development (SPAD) value, LAI, and biomass and grain yields of rain-fed lowland rice were highest with Urea supergranule N fertilizer sources followed by slow-release Urea and conventional Urea applications in both planting methods. Average grain yields of 3.7 and 3.8 tons ha−1 of rain-fed lowland rice were recorded with the application of Urea supergranule N source fertilizer under seedling transplanting and drill row seed planting methods, respectively. Hence, using Urea supergranule tablet is recommendable for getting better grain yield of rain-fed lowland rice without yield penalty in both planting methods.

中文翻译：

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埃塞俄比亚西北部Fogera平原雨养低地水稻对不同氮肥来源、施用方法和时间的生长和产量响应

摘要 在埃塞俄比亚西北部福格拉平原 2017 年和 2018 年的主要种植季节，在育苗和条播播种方式下的两组田间试验并排进行了两年，研究了不同来源、施用方法和时间的影响。氮肥对雨养低地水稻生长和产量的影响。三种氮源肥料（常规尿素、尿素超颗粒和缓释尿素）分别具有六种、一种和三种施用方法和次数，以随机完全区组设计 (RCBD) 布置，分三个重复。这些处理和设计同样适用于两种种植方法下的两组实验。结果显示土壤-植物分析发展 (SPAD) 值、LAI、在两种种植方法中，使用尿素超颗粒氮肥来源的雨养低地水稻的生物量和谷物产量最高，其次是缓释尿素和常规尿素应用。分别在育苗和条播播种方法下施用尿素超颗粒氮源肥记录了雨养低地水稻的平均粮食产量为 3.7 吨和 3.8 吨 ha-1。因此，推荐使用尿素超颗粒片以获得更好的雨养低地水稻的谷物产量，而两种种植方法都不会影响产量。分别在育苗和条播播种方式下施用尿素超颗粒氮源肥记录了8 t ha-1 雨育低地水稻。因此，推荐使用尿素超颗粒片以获得更好的雨养低地水稻的谷物产量，而两种种植方法都不会影响产量。分别在育苗和条播播种方式下施用尿素超颗粒氮源肥记录了8 t ha-1 雨育低地水稻。因此，推荐使用尿素超颗粒片以获得更好的雨养低地水稻的谷物产量，而两种种植方法都不会影响产量。