Studies On Soil Antierodibility Assessment Criteria System In Granite Area

The research was carried out at the granite area,located in Changting county,Fujian province.30 soil samples were chosen ,being from regions with different control practices in 2000,2001,2002,2003.Every sample had three repetitions.On the base of field survey and analysis and by the statistics analysis,the objectives of this paper were to classify the soil samples,build the soil antierodibility assessment criteria system,search for the principal component and gain the various samples' comprehensive score.It was showed that, thirty samples can be classified into five kinds and each kind covered 16.67%, 23.33%, 23.33%, 6.67%, 30% separately;according to the principle of antierodibity-building,significant differences between kinds for most characters tested and larger variance coefficient of the characters in different kinds,the assessment criteria system was established, including erosion ratio,>2mm,l-2mm,organic matter degree,clay ratio,degree of soil particle aggregation,non-capillary porosity,initial infiltration rate, stable infiltration rate;by factor analysis 3 main components were acquired which were called grain and pore component,organic matter and degree of soil particle aggregation component, initial infiltration rate component,every component had a model and each soil sample had a comprehensive score.The principal factor models were:Z₁=0.873X₁+0.867X₂-0.8X₃-0.074X₄+0.104X₅-0.17X₆-0.382X₇-0.027X₈. Z₂=-0.071X₁-0.201X₂+0.023X₃+0.834X₄+0.761X₅+0.693X₆+0.635X₇+0.111X₈. Z₃=-0.082X₁-0.286X₂-0.274X₃-0.246X₄+0.297X₅+0.439X₆+0.099X₇+0.902X₈.The comprehensive score indicated that the score of sample 11 was the highest and sample 17 was the lowest;The score of sample 9,10,11,12,22 were higher and sample 6,18,23,30 was lower;these samples are mainly from various control practices; the years of the control practices,the more years had passed,the soil antierodibility was enhanced greatly;it could be included that the soil antierodibity was not always positive with soil erosion;the soil erosion might be influenced not only by the soil...