Trade-offs among yield, water productivity, water footprint, and economic benefits for wheat production under conservation tillage: A long-term field experiment approach

Abstract

Water footprint (WF) is a water sustainable management indicator that quantifies the virtual water use in crop production. Water productivity (WP) and WF were examined under different tillage practices for wheat (Triticumaestivum L.) in the semiarid Loess Plateau of China. Wheat was grown in 2002 −2017 with six tillage practices: conventional tillage (T), no-till without straw cover (NT), conventional tillage with straw cover (TS), no-till with straw cover (NTS), conventional tillage with plastic mulching (TP), no-till with plastic mulching (NTP). Tillage practices did not significantly increase crop evapotranspiration, but NTS, TP, and NTP reduced soil evaporationwhile increasing transpiration, root growth and biomass accumulation. Additionally, NTS reduced the water consumption during the early stage but increased the water utilization from heading to harvest, while TP, and NTP exhibited the opposite pattern. Wheat yield under TS, NTS, TP, and NTP was higher by13, 28, 22, and 24 %, respectively, than under T, with corresponding improvements in water productivity of 15, 24, 26, and 24 %, respectively. The change in net economic return was 39, 21, 148, −49, and 18 % for NT, TS, NTS, TP, and NTP, respectively, compared to T; the sustainability yield index was 0.45, 0.41, 0.52, 0.55, 0.48 and 0.47, respectively. Total water consumption was significantly increased by 8.2 and 9.8 % under TS and NTS, respectively, compared to T. WF under NTS, TP and NTP was significantly decreased by 18.6, 18.5 and 22.3 % compared to T, respectively. These results suggests that NTS increased yield, economic benefits and WP with less WF through enhancing root growth and water utilization during the filling period. Therefore, NTS represented a sustainable a sustainable water management strategy for wheat in the semiarid Loess Plateau.