Soil Water Dynamics and Winter Wheat Performance under Precipitation Change in the Loess Tableland Region, China

Abstract

The responses of soil water and winter wheat (Triticum aestivum L.) to changes in precipitation are crucial for stability of wheat yield and soil water conservation in the Chinese Loess Tableland Region (LTR). A 2‐yr (2014‐2016) experiment was conducted in the LTR to investigate soil water dynamics and winter wheat performance under three precipitation levels: Rc (normal), R+ (increased by one‐third of normal), and R− (decreased by one‐third of normal) by a real‐time precipitation allocation system. Soil water storage (SWS) at a depth of 0–3.8 m showed positive (R+) or negative (R−) responses to precipitation. The mean SWS in different soil layers followed an order of R+ > Rc > R−. During the experiment, the 0–3.8 m SWS decreased by 34.5 mm (R+), 183.8 mm (Rc), and 218.9 mm (R−). The shoot biomass and grain yield varied little among three precipitation levels in 2014–2015, but was reduced by 50% in R− compared with Rc in 2015–2016. The R− and Rc treatments had higher water use efficiency (WUE) than R+ in 2014–2015, and Rc was the highest in 2015–2016. The proportions of soil water to water consumption in R+ and Rc increased from 22.5% in 2014–2015 to 42.5% in 2015–2016 on average, and for R− was stable over 2‐yr (average 44.5%). Soil water plays a critical role in winter wheat performance under changes in precipitation, which should guide winter wheat production and soil water management in the future. Core Ideas Precipitation changes soil water storage but does not change the regime of soil water changing with time. Response of winter wheat yield to precipitation change has hysteresis effect. Supplementary effect of soil water compensates for the negative effect of decreased precipitation. Performance of supplementary effect is determined by precipitation pattern.

Spatial distribution characteristics of soil moisture in different slopes on Loess Gully Region

“…Soil moisture plays a very important role in vegetation restoration. Some studies focus on soil moisture and its important role in improving crop productivity (Hong et al 2021;Wang et al, 2021;Zhu & Cui, 2019). Likewise, soil moisture is a key factor for vegetation restoration on the Loess Plateau.…”