| With the proposed and popularization of precision agriculture and soil testing and feitilizer recommendation technology,people need to adjust measures to local conditions,time,and physical condition,this makes the research on spatial variability of soil nutrients and influencing factors are great important.This paper as the farming area of Zhouzhi county in Shaanxi Province for example,combining GIS and statistical,analyzes on the soil properties incuding organic matter, alkaline hydrolysis nitrogen,available phosphorus, available potassium and pH.Just want to provide decisions for precision agriculture implementation and optimize the environment of soil. The main results are as follows:(1)Combination of CoKriging technique and multivariate data spatial analysis method,can analyze the spatial variability of soil nutrients and its influencing factors very well,and provide the technical support for analyst soil nutrient in quantitative, visualize methods.As organic matter for example, sample size with85%,it is mean that806sample points,the eatimation accuracy have been raised that the RMSE would cut0.631%and the correlation would increan2.724%.(2)Five variables’ nugget in between31.164%～69.322%,all are the medium spatial correlation. The structural factors and random factors work together to soil nutrient.By analyzing CoKriging interpolation figure, the distribution of pH was significantly decreasing trend from north to south;Alkaline hydrolysis nitrogen is low in the central content,other soil nutrient along the norther Wei River floodplains and southern loess tableland are relatively low.(3)Soil types has the greatest effect in the organic matter and pH,phosphorus is minimal.In terrain factors, elevation with organic matter,pH value was significantly negative correlation,and negatively correlated with pH to slope,elevation and slope have no significant impact on other variables, and same as curvature;Slope to the influence of soil nutrient is greater in sunny slope than the schattenseite.Soil moisture were very significant positive correlation with the N,P,K and organic matter.In terms of land use, except alkali-hydro nitrogen,kiwifruit orchard’s soil nutrient content were greater than the wheat-corn land.The distance to residential areas was significantly positively related to the organic matter, but negatively related to the phosphorus significantly.(4)Agricultural area of Zhouzhi county, the basic state of soil fertility is low. Which requires constant supply of soil organic matter,and the alkaline hydrolysis nitrogen was serious lack,phosphorus and available potassium are relatively lack.Moreover, spatial variation of soil nutrient in the farming area affected by modern agricultural cropping system.When fertilization,be sure to keep in accordance with the spatial distribution of soil nutrients,and fertilization shall be planned the fixed-point,timing and quantitative in order to improve agricultural economic benefit and agricutural ecological environment. |
