Effects of water collection and mulching combinations on water infiltration and consumption in a semiarid rainfed orchard

Abstract

Soil water and its efficient use are critical to sustainable productivity of rainfed orchards under the context of climate change in water-limited areas. Here, we combined micro-catchments for collecting hillslope runoff, named fish-scale pits, with mulches to examine water infiltration and water consumption of fruit trees using in situ soil moisture monitoring, the micro-lysimeter and sap flow methods via a two-year experiment in a rainfed jujube orchard on China’s Loess Plateau. This experiment included four treatments: fish-scale pit with branch mulching (FB), fish-scale pit with straw mulching (FS), fish-scale pit without mulching (F), and bare land treatment (CK). The results showed that only about 50% of the rainfall infiltrated the soil for CK during the 2014 and 2015 growing seasons. The fish-scale pit without mulching experienced significantly increased rainfall infiltration by 41.38 and 27.30%, respectively, but also increased evaporation by 42.28 and 65.59%, respectively, compared to CK during the two growing seasons. The jujube transpiration significantly increased by 45.64–53.10% over CK, and the evaporation decreased by 42.47–53.50% when fish-scale pits were mulched with branches or straw. Taken together, the results show that the fish-scale pits and mulching combinations efficiently increased rainfall infiltration and jujube evapotranspiration in the experimental jujube orchard. The findings here provide an insight into the field water management for hillslope orchards in water-limited regions.