Crop yield and irrigation water productivity of silage maize under two water stress strategies in semi-arid environment: Two different pot and field experiments

Research on water stress strategies (WSS) and crop response to water stress is important to improve irrigation water productivity (WPI) and crop production especially for regions where water is a limited resource. This study was conducted to assess (i) the response of silage maize to water stress at different growth stages for contrasting water stress strategies in the semi-arid environment under pot and field experiments irrigated by a drip-tape system, (ii) to determine the relationship between applied water and total biomass (TB) in different WSS in both experiments. The hybrid 704-single-cross of maize was assessed at pot experiment during 2009 and 2010 and field experiment was conducted in 2017 under two WSS including WS1 (same irrigation event with different applied water depth) and WS2 (same applied water depth in different irrigation event) at three growth stages. Each WSS consisted of four different irrigation levels, including severe, moderate, and mild drought stress and a full irrigation. In both pot and field experiments, severe drought stress under WS1 and WS2 strategies led to a depression in LA and TB at tassel (S2) and silage harvest (S3) stages. At each growth stage, WPI values decreased with increasing water-deficit levels in both WSS's and experiments. We found a linear relationship between TB and applied water for WS1 and WS2 in both experiments. However, the yield performance per unit of water used was higher for WS1 than for WS2. The yield response factor to stress (Ky) values for LA and TB were higher under WS2 than WS1 in both experiments, indicating that WS1 can be employed as an effective deficit irrigation management under the drip-tape irrigation system for maize in an arid area with shortage of water.