Abstract Water productivity benchmarks for irrigated and rainfed agriculture will provide relevant information to manage scarce water resources and control groundwater level decline. We analyse the temporal and spatial variation of the water productivity (WP) of maize and soybean in Nebraska, with WP defined as harvested crop weight per total evapotraspiration. The results show that WP of both maize and soybean increase from west to east within Nebraska and have increased over the last 25 years, mainly due to the increase in crop yields (land productivity). We derive WP benchmarks for each crop per climate zone. Increasing actual WPs in the state to benchmark levels will increase yields by 21 % for maize and by 19 % for soybean. The WP benchmark levels for the two crops presented here will help formulating targets for closing water productivity gaps and improving the sustainability of water use in the state.

中文翻译：

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水生产力基准：内布拉斯加州的玉米和大豆案例

摘要 灌溉和雨养农业的水生产力基准将为管理稀缺水资源和控制地下水位下降提供相关信息。我们分析了内布拉斯加州玉米和大豆的水分生产力 (WP) 的时空变化，WP 定义为每总蒸发量的收获作物重量。结果表明，内布拉斯加州内玉米和大豆的 WP 从西向东增加，并且在过去 25 年中有所增加，主要是由于作物产量（土地生产力）的增加。我们为每个气候区的每种作物推导出 WP 基准。将该州的实际 WP 增加到基准水平将使玉米的产量增加 21%，大豆的产量增加 19%。