Water productivity of two wheat genotypes in response to no-tillage in the North China Plain

Uneven distribution of precipitation and overexploitation of groundwater resources threatens the sustainability of agriculture in the North China Plain. Adoption of water deficit-tolerant winter wheat genotypes coupled with timely, adequate farming practice is crucial to enhance sustainable crop production and water productivity in the region. The present study aimed to evaluate water consumption patterns and water productivity of two winter wheat genotypes (Tainong-18 and Jimai-22), under no-tillage or conventional tillage, over a period of four consecutive cropping seasons. Under no-tillage, Tainong-18 showed the lowest soil moisture consumption before sowing in the 30–110 cm soil profile. Jimai-22 under conventional tillage and Tainong-18 under no-tillage showed the highest and lowest evapotranspiration across cropping seasons, respectively. Compared with conventional tillage, no-tillage reduced grain yield and water productivity of winter wheat, and the difference between them increased for grain yield (6.79, 11.99, 14.78, and 15.73%) and water productivity (0.99, 8.14, 12.18, and 13.30%) over the 2015–2016, 2016–2017, 2017–2018, and 2018–2019 cropping seasons, respectively. In contrast, Tainong-18 showed lower evapotranspiration and increased grain yield and water productivity compared with Jimai-22. Further, Tainong-18 showed a compensatory effect on the reduction of water productivity under no-tillage, compared with Jimai-22. Our conclusions indicate that the combination of no-tillage and water-efficient winter wheat genotypes is an effective strategy to offset the reduction in water productivity caused by no-tillage and thus maximise water productivity in the North China Plain.