渭北果园不同管理措施的土壤水分灰色关联度

Grey Relational Analysis of Soil Moisture Under Different Management Measures in Orchards of Weibei

为了解果园土壤水分的剖面和季节变化特征,运用灰色关联分析法,分析了渭北黄土高原苹果园在3种不同土地利用类型下土壤水分的垂直变化和月动态。结果表明:不同土地利用类型的土壤水分垂直变化规律不尽相同,深层(120—160cm)与底层(160—200cm)土壤水分变化态势的相似程度均较高,即土壤水分的变化发展态势较一致,但相似程度清耕>草地>秸秆,表层(0—40cm)、浅层(40—80cm)与底层的灰色关联度最小,土壤水分变化态势差异最大。由各月土壤水分灰色关联度可知,清耕6—7月份与5月份的土壤水分灰色关联度处于中间水平,土壤水分变化态势的相似程度一般,8月份的差异明显;草地6—8月份的灰色关联度较大,土壤水分灰色关联度有波动,变化趋势为大—小—大—小—小—大;而秸秆地6—7月份与5月份的土壤水分灰色关联度相对较大,其他各月之间水分变化态势相似度较小。灰色关联分析法可以较好地反映不同土地利用类型土壤水分变化趋势的相异或相似性。

In order to investigate soil moisture profile and seasonal variation characteristics,based on the method of grey correlation analysis,we analyzed the vertical and monthly dynamic change of soil moisture content under 3land use types of apple orchard in Weibei in the Loess Plateau.The results showed that the vertical change of soil moisture content under different land use types were quite different.In deep layer（120—160cm）and bottom layer（160—200cm）,the variation of soil moisture was highly accordant,and the change of soil moisture development trend was consistent with an order of clear tillage〉grassland〉straw mulch land.Grey relational grade of the all land uses between top layer（0—40cm）and shallow layer（40—80cm）was less,which meant that soil moisture varied remarkably.In clear tillage,grey correlation degrees of soil moisture between June to July and May were at the middle level,however,remarkable difference was found in August.In grassland,grey correlation degree of soil moisture was high during the period from June to August,and the fluctuation of soil moisture in growth season was great with the change trend of high—low—high—low—low—high.Grey correlation degrees of soil moisture between June to July and May were at the high level in straw mulch land,however,the variation trend of soil moisture in other months was low.The method of grey correlation analysis can be used to ideally identify the dissimilarity or similarity of soil moisture content change under different land use types.