Shaanxi Provincial Land Engineering Construction Group Co., Ltd., Institute of Land Engineering and Technology, Xi'an, China.
Shaanxi Key Laboratory of Land Consolidation, Xi'an, China.
PeerJ. 2023 Mar 30;11:e15098. doi: 10.7717/peerj.15098. eCollection 2023.
Agricultural production in the Weibei rainfed highland, Northwest China, is challenged by severe drought and water shortages. While the land use pattern has shifted gradually from crop production to orchard farming in Weibei, little is known about the influence of fruit industry development on regional water resources and the rationality of planting orchards. Here, we characterized soil water depletion patterns in rainfed orchards and farmlands to evaluate the occurrence of soil desiccation under land use conversion from farmlands to orchards in Weibei. Soil moisture dynamics were monitored in the 0-150 cm soil profiles of different aged Red Fuji apple orchards (young: 7 years, mature: 13 years, old: 22 years) and long-term cultivated winter wheat fields. We measured soil moisture content by oven-drying method in the middle of each month during the growing season of apple trees (March-September 2019). The over-depletion and depletion of soil water were analyzed to evaluate water stress and differential water depletion by distinct vegetation, respectively. The soil desiccation index was used to determine the occurrence of dry soil layers. Water stress was only observed at the 0-70-cm soil depths in the old orchards (mid-June) and farmlands (mid-May-mid-July). Water depletion took place at deeper depths for longer periods in the older orchards than in the younger orchards. Soil desiccation was absent in the young orchards, with mild desiccation at the 0-80-cm soil depths in the mature and old orchards in mid-June. The desiccation intensity was mild at the 0-60-cm soil depths in mid-April-mid-May, intense at the 0-150-cm soil depths in mid-June, and moderate at the 20-150-cm soil depths in mid-July. Results of this study demonstrate the mitigation of water stress and soil desiccation following conversion from wheat fields to apple orchards, which verifies the rationality of planting orchards in the rainfed highland area. Our findings provide strong support for developing a novel model of agro-industrial development, ecological construction, and sustainable economy in the vast arid and semi-arid areas of Northwest China.
中国西北渭北旱塬的农业生产面临着严重干旱和水资源短缺的挑战。尽管渭北的土地利用模式已逐渐从作物种植转向果园种植，但对于果业发展对区域水资源的影响以及果园种植的合理性知之甚少。在这里，我们描述了雨养果园和农田的土壤水分消耗模式，以评估渭北从农田向果园转变过程中土壤干燥的发生情况。在不同树龄的红富士苹果园（幼龄：7 年，成熟：13 年，老龄：22 年）和长期种植冬小麦的农田中，监测了 0-150cm 土壤剖面的土壤水分动态。在苹果树的生长季节（2019 年 3 月至 9 月），每月中旬通过烘箱干燥法测量土壤含水量。分析了土壤水分超耗和耗竭情况，分别评估了不同植被的水分胁迫和差异耗水情况。土壤干燥指数用于确定干土层的发生情况。仅在老龄果园（6 月中旬）和农田（5 月中旬至 7 月中旬）的 0-70cm 土壤深度观察到水分胁迫。老龄果园的土壤水分消耗深度更深，时间更长。在幼龄果园中不存在土壤干燥，而在成熟和老龄果园中，6 月中旬在 0-80cm 土壤深度出现轻度干燥。4 月中旬至 5 月中旬，0-60cm 土壤深度的干燥强度较弱，6 月中旬，0-150cm 土壤深度的干燥强度较强，7 月中旬，20-150cm 土壤深度的干燥强度适中。本研究结果表明，从麦田向果园的转变减轻了水分胁迫和土壤干燥，验证了在雨养旱地种植果园的合理性。我们的研究结果为在我国广大干旱半干旱地区发展新型农业产业发展、生态建设和可持续经济模式提供了有力支持。
