Spatial Characteristics of Soil Moisture of Apple Orchards in the Loess Plateau of Shaanxi Province | 陕西黄土高原苹果园土壤水分分异特征

Chinese. 采用定点监测法,对陕西省不同区域、生长年限、立地类型以及乔矮化果园的土壤水分分异特征进行研究。结果表明：陕西苹果园由南向北土壤贮水量逐渐降低,土壤水分亏缺加重;在干旱季节,北部丘陵沟壑区果园土壤水分亏缺度高达18.5%～47.5%,黄土残塬区为7.8%～20.3%,关中平原仅有1.2%～6.3%;在生长季内,随土壤深度增加,土壤含水量变异程度减弱;北部丘陵沟壑区的变化主要发生在2.2m以上土层内,CV值达12.67%～35.32%;黄土残塬区主要在1.8m以上土层内,CV值11.72%～24.54%;关中平原主要在1.2m以上土层内,CV值13.63%～20.76%;同一区域的果园土壤剖面贮水量随果树年龄增大而下降;在北部丘陵沟壑区,坡地的土壤水分含量最高,台地次之,梯田地相对较低;在残塬沟壑区,塬地的土壤水分含量最高,川地次之,台地相对较低;同一密度矮化果园的土壤含水量高于乔化果园,但栽培密度大的矮化果园土壤贮水量低于密度小的乔化果园。

English. By means of fixed-point monitoring, in this paper, we investigated variation in soil moisture at apple orchards in different regions, with different growth years and different site types, as well as ordinary and dwarf apple trees were studied in Shaanxi Province by fixed spot surveillance. The results showed that soil water storage of the apple orchards in Shaanxi reduced gradually from south to north, and the soil water deficit was exacerbated. In the dry season, the degree of soil water deficit was up to 18.5%-47.5% in hilly and gully regions of Northern Shaanxi, was 7.8%-20.3% in valley and gully region of the Loess Plateau, and was only 1.2%~6.3% in Guanzhong Plain. In growth season, variation range of soil moisture content reduced with increased soil depth in the apple orchards. The change of soil moisture content mainly occurred in 0-2.2 m in hilly and gully region of Northern Shaanxi and the coefficients of variation （CV） were 12.67%-35.32%, in 0-1.8 m in valley and gully region of the Loess Plateau with CV of 11.72%-24.54%, and in 0-1.2 m in Guanzhong Plain with CV of 13.63%-20.76%. Soil water storage declined with increase of growth years in the apple orchards within a region. In hilly and gully region of Northern Shaanxi, soil moisture content was highest in sloping land, followed by platform, and then terraced field. In valley and gully region of the Loess Plateau, soil moisture content in highland was highest, followed by flat land, and then platform. Soil moisture of dwarfing orchards was higher than ordinary orchards with the same stand density, but soil water storage of dwarf orchard with higher stand density was lower than ordinary orchards with lower stand density.