陕北黄土区山地苹果园土壤水分动态变化特征研究

Study on soil moisture dynamic characteristics of apple orchard in the Loess plateau of northern Shaanxi

以八年生矮化红富士果树为试材,采用野外定位观测法,对陕西省延安地区苹果园0~100 cm不同深度土壤水分与温度及相应气象要素进行连续1年的定位观测分析,对土壤水分的动态变化规律、时空变化及影响因子进行研究。采用方差分析、相关性和主成分分析方法探讨土壤水分的主导因素及其相互关系。研究表明:观测期土壤墒情的季节变化可划分为水分快速消耗期(4—6月)、水分恢复期(7—10月)、稳定期(11—次年3月);土壤体积含水量由浅到深呈先增后减、稳定性增强、垂直变化季节差异显著等特点;主成分分析结果表明,第一主成分中土壤温度及电导率所占比重较大,第二主成分中大气温度和湿度指标权系数的绝对值在所有主成分指标系数中是最大的,降雨量是第三主成分中标权系数最大的;研究区降雨量季节分配极不均匀,主要集中在生长季7—9月,占全年降雨量的73.5%,不同月份、深度的土壤水分变异系数均属于中等程度变异,土壤水分与大气温度、电导率降雨量、相对湿度、降雨量表现出极显著正相关关系,而与风速呈极显著负相关(P<0.01)。该研究揭示了山地苹果园土壤水分的变化规律,可为黄土高原地区果园的建设和管理提供理论依据。

Eight-year-old dwarf red Fuji apple trees were used as materials,the field positioning observation method was used to locate and analyze soil moisture and temperature and corresponding meteorological elements at different depths ranging from 0-100 cm in Yan'an area,Shaanxi Province for one consecutive year,and the dynamic change law,temporal and spatial changes and influencing factors of soil moisture were studied.ANOVA,correlation and principal component analysis methods were used to explore the dominant factors of soil moisture and their interrelationships.The results showed that the seasonal changes of soil moisture during the observation period can be divided into rapid water consumption period(April to June),water recovery period(July to October),and stable period(November to March of the following year).The soil volume water content increased first and then decreased,the stability was enhanced,and the vertical change was significantly different in season.The results of principal component analysis showed that soil temperature and conductivity accounted for a large proportion in the first principal component,the absolute value of the atmospheric temperature and humidity index weight coefficient in the second principal component was the largest among all principal component index coefficients,and the precipitation was the largest standard weight coefficient in the third principal component.The seasonal distribution of precipitation in the study area was very uneven,mainly concentrated in July to September of the growing season,accounting for 73.5%of the annual precipitation,and the coefficient of variation of soil moisture in different months and depths was moderately variable,and soil moisture showed a significant positive correlation with atmospheric temperature,conductivity precipitation,relative humidity and precipitation,and was negatively correlated with wind speed(p<0.01).This study reveals the variation of soil moisture in mountain apple orchards,which provides theoretical reference for the construction and management of orchards in the loess plateau.