Research On Spatial Variability Of Soil Nutrients In Shouxian County

In soil nutrients there is a general spatial variability.Explore the distribution of soil nutrients is conducive to nutrient partition management and guide farmers to rational fertilization.This article selects Shouxian as the research area,and uses traditional statistical methods to study the basic statistical characteristics of soil nutrient organic matter,available copper,available iron,available zinc,available potassium,and available phosphorus,and compares it with the results of the second soil survey.Using GIS combined with GS technology the spatial variability of selected soil nutrients was studied,the best semi-variogram model of soil nutrients was constructed,spatial interpolation was performed based on the obtained parameters,and the main factors affecting the spatial variability of nutrients were explored,in order to provide an important basis for promoting the management and rational fertilization of cultivated soil nutrients in the study area.Main results are as follows:(1)Descriptive statistics on the basic characteristics of soil nutrients in Shouxian.From the coefficient of variation,the coefficient of variation of soil nutrients was between 18.57%and 47.63%,which also belonged to moderate variation.Among them,organic matter has the smallest coefficient of variation of 18.57%,and effective iron has the largest coefficient of variation of 47.63%.The coefficient of variation from large to small is:available iron,available zinc,available phosphorus,available potassium,available copper,organic matter.(2)The exponential function is the best semivariogram of selected soil nutrients.From the nugget coefficient,the nugget effect of soil nutrients is form 9.2%to 11.1%,both of them are strongly spatial correlation.According to the regional distribution of soil nutrients content,we can see the distribution of soil nutrients in different regions and different nutrients in the same region is different,and the complexity of the distribution of a large number of nutrient elements is less than the complexity of the distribution of micronutrients elements.The spatial distribution of organic matter is decreasing from southwest to northeast,and is distributed in flaked;the content of available phosphorus is higher in the middle and lower in the northwest;the content of available potassium is lower in the north and higher in the south.The contents of available zinc,available iron,and available copper in the micronutrients were not high as a whole,and there was no obvious spatial distribution pattern and the spatial distribution was blocky.(3)Soil nutrients in Shouxian have a nugget coefficient of less than 25%and have strong spatial variability.This shows that the natural factors is the main factor of spatial variability of soil nutrients,and the influence of human factors is small.The analysis results of the factors affecting the soil texture show that the available potassium and available iron content are greatly affected.In terrain condition factors,there is a positive correlation between available potassium and slope,and there is a negative correlation between other soil nutrients and slope.Among the land-use types,the content of organic matter and available phosphorus in wheat-cotton land was greater than that in wheat-rice and oil-rice,and the content of available iron was highest in oil-rice land,and the content of available phosphorus,available copper,and available zinc were the highest in the wheat-rice land.In the landform type,the overall soil nutrient content in the slope land is high,which may be related to soil type and parent material.(4)In the study of reasonable sampling points,using organic matter as a reference,when the number of sample points is reduced to 85%or 1090,the spatial distribution of organic matter can be predicted,and the prediction accuracy is high,which can save time and cost.