Study On The Soil Nutrients Spatial Variability And Reasonable Distances Of Soil Sampling Design Under The Village Level Scale Of Karst Regions In Guizhou Province

SummaryThe configuration and forming process of soil is very complex and soil properties have high spatial variability.Human activities further strengthened the variability.It is significant to study the spatial variability of soil properties and reasonable distances of soil sampling design under the village level scale for carry out precision farming in dispersing agriculture management system of Karst Regions in Guizhou Province.According the above conclusion,we can put into exactitude amount production materials at the apt time and appropriate area.At the same time,we can establish the base for improving the yield,saving the investment and amending the environment. This study also can offer the reference for carving up the district of precision farming management and the arable farming measure of the decision-making district.This paper was based on the data of soil fertility survey of of Pingba county's Limu villiage in Guizhou Province.The county can be divided into two regions according to the landform,dry land and paddy field.The classic statistic,geostatistical analyst and the technology of geography information system were used to analyze and compare the spatial variability of thirteen kinds of soil properties pH,organic matter,ammonium nitrogen,available phosphorus,potassium,calcium, magnesium,sulfur,boron,cuprum,iron,manganese and zinc.Advisable number of soil sampling in a given area had been suggested in this paper.Research results were as followed.From the coefficient of variation,we can find that there is a big difference among the different Soil nutrients in the whole research area.There is a big difference among the different Soil nutrients between dry land and paddy field,which is smaller than the variation of the whole area.This statistic datas illuminate that the spatial variability of soil properties have some thing to do with different farming utilize types.The variation coefficient amplitude of the whole area is highest and the variation coefficient amplitude of paddy field is lowest,the dry land's variation coefficient amplitude is between them.The spatial variability of soil properties of the different farming utilize types are similar in the same research area.Different soil properties have a big spatial variability.From the average data of the soil properties,we can find that there is only little difference in the soil pH,organic matter and zinc.The content of calcium,magnesium and cuprum in paddy field is much higher than which in dry land.The content of ammonium nitrogen,available potassium,sulfur,boron,cuprum,iron and manganese in paddy field is little higher than in dry land.However,The content of available phosphorus in paddy field is much lower than it in dry land.This study result indicate that 50 meters multiply 50 meters' sampling distance which be used by this item is satisfied with the experiment require.In the dry land of research area,soil properties pH,calcium,magnesium,sulfur,boron,iron and manganese have strong space correlation.Organic matter,available phosphorus,potassium and zinc only have a little space correlation.Ammonium nitrogen and cuprum's space correlation between the two formers.In the paddy field of research area,soil cuprum have strong space correlation.Organic matter,sulfur and boron only have a little space correlation.Soil properties pH, organic matter,ammonium nitrogen,available phosphorus,potassium,calcium,magnesium,iron, manganese,and zinc's space correlation between the two formers.According to analyzing the database and the distributing map of soil properties,we point out which soil propertie is lack and which is enrich.At the same time,we give the good advice for how to increasing the fertilizer of the lack soil properties.We find out the best interpolation method and the higher precision and more economic sampling distance of every soil propertie from the different spatial variability of soil properties.