Mulching measures improve soil moisture in rain-fed jujube orchard in the loess hilly region of China

Abstract

BackgroundWater shortage is the main bottleneck restricting the healthy and sustainable development of rain-fed jujube orchards in the loess hilly region of China. Given the functions of mulching on soil moisture conservation, evaporation reduction, and water use efficiency improvement, maize straw mulching (SM) and pruned jujube branch mulching (BM) were applied to rain-fed jujube orchards in this study. Soil moisture dynamics, soil water storage, water consumption, and soil moisture attenuation after typical rainfall under SM, BM, and clean tillage (CT) were systematically studied. Results(1) The 0-60 cm soil layer was the seasonal fluctuation layer of soil moisture under SM, BM, and CT in both the normal precipitation year and the dry year. The 0-60, 60-160, and 160-280 cm soil layers under CT all obtained the lowest soil moisture content in the three experimental years. The soil moisture content of each soil layer under SM and BM was higher than that under CT, and SM showed the most obvious effect of increasing soil moisture. (2) SM and BM showed significant soil water storage effect in all the jujube growth stages in both the normal precipitation year and the dry year, and SM had a better water storage effect than BM. (3) SM and BM reduced the water consumption amount in each jujube growth stage. SM reduced water consumption amount by 94.3, 60.8, and 121.3 mm compared with CT in the whole growth period of jujube in 2014, 2015, and 2016, respectively. The water consumption amount of BM decreased by 34.8 mm and 31.0 mm respectively compared with that of CT in the whole growth period in 2014 and 2015. (4) CT had the maximum soil moisture loss rate under continuous drought after rainfall. The soil moisture loss rate of CT was above 37.3% on the eleventh day after the typical rainfall in 2014, 2015, and 2016. With the extension of drought, the soil moisture loss rate under SM increased slowly, while it increased rapidly under CT. ConclusionThis study suggests that straw mulching is the best mulching measure for rain-fed jujube orchards, and the pruned jujube branches can also be used for in-situ mulching, which can also obtain a certain moisture conservation effect.

Jujube is at a competitiveness disadvantage to cotton in intercropped system

“…While jujube/cotton (Gossypium hirsutum L.) intercropping is common throughout the area, farmers cannot often provide the optimal amount of irrigation. Previous studies demonstrate that soil moisture is a key factor affecting crop yields in intercropping, where the redistribution of water alters crop yields (He et al, 2016;Ling et al, 2016). Historically, research has focused on the effect of water deficit on agroforestry and crop yields (Li et al, 2014;Wu et al, 2016), but these studies did not systematically investigate the competitive behavior of the intercropping system when the water is insufficient.…”