丹江鹦鹉沟小流域土壤全磷空间分布及流失特征

The spatial distribution and loss of soil total phosphorus in Yingwugou Watershed of Danjiang River

磷是植物生长和水体富营养化的主要限制因子。本文选取南水北调中线工程丹江水源区的鹦鹉沟小流域作为研究区域,通过采集土壤样品和监测不同土地利用类型的土壤磷素流失状况,采用经典统计学与地统计学相结合的方法,研究了流域土壤全磷的空间异质性,结合不同土地利用方式下的土壤全磷含量与流失浓度分析其流失特征。结果表明：鹦鹉沟流域土壤深度0～10 cm（A_1）、10～20 cm（A_2）、20～40 cm（A_3）和40～60 cm（A4）的全磷含量平均值分别为0.54 g/kg、0.49 g/kg、0.48 g/kg和0.51 g/kg,经ANOVA检验,不同深度的土壤全磷含量存在显著性差异（P〈0.05）;Kriging插值表明流域土壤全磷的空间分布呈现斑块状特征,其分布斑块随土壤深度增加逐渐由大变小。不同土地利用方式下园地、草地与耕地的土壤全磷含量存在显著性差异（P〈0.05）;耕地中花生、玉米、萝卜、豆角、辣椒的总磷流失浓度均高于草地,而草地的速效磷流失浓度高于玉米、豆角和花生。

Phosphorus is the major limiting element for plant growth and water body eutrophication. This paper selects Yingwugou Watershed in the Danjiang water resource area of the middle route engineering of South-to-North water diversion project served as the research region. Soil samples are collected and soil phosphorus loss conditions in different types of land use are monitored. The classical statistics combined with the geostatistics can be used to study the spatial heterogeneity of soil total phosphorus（ STP） in the whole watershed,and the nutrient loss behaviors are analyzed in combination of STP contents with loss concentration under the different types of land use. The research results indicate that the average value of STP contents in 0 ～ 10 cm（ A_1）,10 ～ 20 cm（ A_2）,20 ～ 40 cm（ A_3） and 40 ～ 60 cm（ A_4） in Yingwugou Watershed are 0. 54 g / kg,0. 49 g / kg,0. 48 g / kg and 0. 51 g / kg,respectively. ANOVA tests indicate that STP content of different depth are significant（ P〈 0. 05）. Kriging interpolation value shows that STP spatial distribution in the whole watershed appears to be patchy,and STP distribution patch area become from big to small with an increase in soil depth gradually. There exists the significant difference（ P 〈0. 05） under the different types of land uses such as tea grove land,grassland and cultivates land. Among the cultivated land,total phosphorus loss concentration in peanut land,maize land,turnip land,bean land and pepper land is higher than that in grassland,but available phosphorus loss concentration in grassland is higher than that in maize,bean and peanut lands.