Soil water and root distribution of apple tree (Malus pumila Mill) stands in relation to stand age and rainwater collection and infiltration system (RWCI) in a hilly region of the Loess Plateau, China
Soil water and root distribution of apple tree (Malus pumila Mill) stands in relation to stand age and rainwater collection and infiltration system (RWCI) in a hilly region of the Loess Plateau, China
复制标题
DOI：
10.1016/j.catena.2018.06.026
复制
发表时间：
2018-11
期刊：
影响因子：
6.2
通讯作者：
Xiaolin Song;Xiaodong Gao;M. Dyck;Wei Zhang;Pute Wu;Jie Yao;Xining Zhao
中科院分区：
文献类型：
--
作者：
Xiaolin Song;Xiaodong Gao;M. Dyck;Wei Zhang;Pute Wu;Jie Yao;Xining Zhao
土壤水分状况和细根分布是半干旱雨养果园实施水分管理的基础。由于半干旱地区地下水普遍缺乏，雨水利用是缓解半干旱地区水资源短缺的有效途径。采用时空替代方法，研究了中国半干旱黄土高原雨养苹果园（Malus pumila Mill）不同林龄（6、9、12、18和21年）的土壤水分和根系分布，以及雨水收集和渗透系统（RWCI）对中国半干旱黄土高原成熟苹果园（21年）根区土壤水分和细根分布的影响。结果表明，浅层（<2m）土壤平均含水量（SMC）随着苹果树龄（6~18年）的增加而降低；大多数情况下，深层SMC（>2m）高于浅土层（<2m），并且各年龄段林分SMC随着深度的增加而增加。细根（直径<2mm）随着苹果树龄的增加，呈明显延伸更深的趋势——12年树龄的苹果园近8m，>12年树龄的>8m。干根重量密度（RWD）随着深度的增加而急剧下降，但在较老的林分中，每个深度的密度都较大。 RWCI系统显着增加了从地表到最大降雨入渗深度（MRID）（2m深度）的SMC（P<0.05），特别是在0.2-1m土层。此外，我们发现，当采用 RWCI 系统和少量灌溉水时，可以可持续地满足苹果树的需水量。根系分布受RWCI系统影响较大，导致RWCI系统下浅土层（2m土深）靠近湿润区的根系密度较高，直至土壤深度3m。总体而言，RWCI系统的应用可以成为一种有效的水管理策略，为半干旱果园提供可持续的水资源。
Soil water status and fine root distribution is the basis of implementing water management in semiarid rain-fed orchards. Exploitation of rainwater is an effective avenue for alleviating water scarcity in semiarid regions since ground water is generally unavailable there. Through the method of space-for-time substitution, we investigated the soil moisture and root distribution along a range of stand ages (6, 9, 12, 18 and 21 years) in rain-fed apple (Malus pumila Mill) orchards and the effects of rainwater collection and infiltration systems (RWCI) on root-zone soil water and fine root distributions in matures apple orchards (21 years) in the semiarid Loess Plateau of China. The results showed that the mean soil moisture content (SMC) in the shallow layer (<2 m) decreased with apple tree age (6 to 18 years); the deep SMC (>2 m) was higher than shallow soil layers (<2 m) in most cases and the SMC increased with depth in stands of all ages. Fine roots (<2 mm diameter) showed an obvious trend of extending deeper with apple tree age - nearly 8 m in a 12-yr-old apple plantation and >8 m in plantations >12 years old. Dry root weight density (RWD) decreased sharply with depth, but densities at each depth were greater in older stands. The RWCI system significantly increased SMCs from the surface down to the maximum rainfall infiltration depth (MRID) (2 m depth) (P< 0.05), especially in the 0.2–1 m soil layer. Further, we found that apple tree water requirements could be sustainably met when RWCI system and a low-volume of irrigation water was applied. The distribution of root system was greatly affected by the RWCI system, which led to higher root densities close to the wetted area in the shallow soil layers (2 m soil depth) under RWCI system, down to a depth of 3 m in the soil. Overall, the application of RWCI system could be an effective water management strategy for providing sustainable water resources for semiarid orchards.