Prof. Shulan Zhang
Affiliation: College of Natural Resources and Environment
Interests: Water and nutrient management on dryland cereals (wheat, maize); Response of soil fertility to nutrient management.
Title of presentation: Attainable water use efficiency and management strategies of dryland wheat/maize in the China Loess Plateau
Due to the pressure of water scarcity and population growth in arid and semi-arid regions, improving crop yield and water use efficiency (WUE) is critical. Here we discuss the attainable WUE of dryland wheat and maize and management strategies in the China Loess Plateau. Under different management practices wheat yield was between 818 and 7900 kg ha-1, the WUE was between 3.4 and 23.4 kg ha-1 mm-1, and the attainable WUE was 26 kg ha-1 mm-1. The yield of maize varied from 1.12 to14.6 Mg ha-1, the WUE varied from 2.8 to 39.0 kg ha-1 mm-1, and the attainable WUE was 45 kg ha-1 mm-1. The yield and WUE were the highest under plastic film mulching, and the lowest yield and WUE under no-till or conventional tillage conditions. Nevertheless, regional meta-analysis found that partial-film mulching and full-film mulching had similar yields and WUE. Besides crop variety, soil fertility and nutrient management also impacted crop yield and WUE. For both wheat and maize, the changes in yield and WUE were mainly related to the changes in the proportion of soil evaporation to total evapotranspiration (ET) and changes in the proportion of ET before and after anthesis. In conclusion, closing the yield and WUE gaps of the dryland wheat/maize on the Loess Plateau requires the integrated management practices, including variety, soil fertility, nutrient management, reasonable mulching measures (e.g. tillage) etc.