水保所知识产出(1956---)知识库

Agriculture’s need to feed the growing population is challenged by the decline in available water resources
especially in the context of global climate change. Improving crop water use efficiency (WUE) will help to
safeguard the environmental sustainability of food production in dryland areas. However, the impact of drought
on crop WUE varies—a comprehensive and quantitative understanding of relevant factors is needed to support
evidence-based management decisions. Here, we used a meta-analysis of global drylands (81 studies with 836
paired observations) to evaluate the response of various crop WUEs to drought based on various natural and
human induced factors. Our results showed that responses of crop types’ WUE varied under drought intensity,
which probably a reference for crop selection in drylands. Cotton could be one of crop selection reference in
hyper-arid or arid regions, and legume is not recommended for drylands without irrigation. Cereal crop are
suitable for growing in semi-arid or dry sub-humid areas. Moreover, soil improvement and fertilizer management
are the effective methods to alleviate drought stress, in addition to irrigation. Soil with medium-texture, 1.3–1.4
g cm −3 bulk density and 15–20 g kg −1 organic matter is beneficial for improving WUE under drought. Fertilizer
should be carefully considered and not exceed 200 kg ha −1 for wheat in drylands. Water deficit can improve crop
WUE, but should not exceed 40% of the full irrigation amount. Field management practices, such as mulching
and weed control, can help alleviate drought by regulating WUE to some extent. This study evaluated the re-
sponses of various crop WUEs to drought and highlighted the factors contributing to and/or decreasing crop WUE
from natural factor and management practices, which provides a basis for agricultural drought mitigation
strategies under future climate change in dryland areas.