Study On The Effect Of Sampling Density On Spatial Variability Of Soil Nutrients

The soil nutrient existed spatial variability,spatial variability of soil nutrients in the study area and spatial interpolation of soil nutrients on regional agricultural fertilization guidance plays an important role,therefore,based on the two research area in Shouxian County as an example,the combination of traditional statistics and geostatistics,selected four soil nutrient indexes(total nitrogen and available phosphorus.,available potassium,organic matter)and analyzed the spatial variation characteristics of these four kinds of nutrients,construct the semi variance function model of the best of them,the spatial interpolation of nutrient using the model parameters,the prediction accuracy compared to complete spatial interpolation.According to the results of the four kinds of nutrients can be understood in the region of the reasonable sampling methods and find the reasonable nutrient density,the spatial interpolation method can have reasonable fertilization agriculture specific guidance in Shouxian County,improve the efficiency of agricultural production.The main results are as follows:(1)Four kinds of soil nutrients in study area are spatial structural variation,coefficient of variation from the perspective of three major elements: soil total nitrogen,soil available phosphorus,soil available potassium and soil organic matter are moderate variability.(2)The nutrient elements of regional independent validation and paired t test showed that nutrient spatial interpolation in different regions of the differences in forecast accuracy,the same area of the different sampling methods of spatial interpolation precision difference.In general,with the decrease of sampling density,the prediction accuracy of soil spatial interpolation is also reduced,and the sampling density is positively correlated with the spatial interpolation prediction accuracy.Can be divided into various regions based on the planning and management of the region,in the agricultural production of reasonable fertilization.(3)Four kinds of soil nutrients using ordinary Kriging prediction research area in West Lake plain farm life,total nitrogen and organic matter by single point sampling interpolation prediction precision,the reasonable sampling density is 0.75/hm~2;single point phosphorus and potassium sampling should increase the sampling density can be predicted spatial interpolation,using mixed sampling method of reasonable sampling density is 0.27/hm~2,to carry out spatial interpolation prediction.An Fengzhen study area hillock area,total nitrogen,available potassium and organic matter by single point sampling interpolation prediction precision,the reasonable sampling density is 1.35 /hm~2;single point sampling spatial correlation is weak,not suitable for spatial interpolation prediction using mixed sampling method of effective phosphorus mixture sampling density 0.23/hm~2.The spatial variability of nutrients was small,and single sampling and Nutrient Spatial variability were used.(4)The whole region four nutrient index into the traditional statistical analysis,the results are as follows: the research of regional soil total nitrogen,soil available phosphorus,soil available potassium and soil organic matter content of the average value of the classification standard of nutrients,the study area of Shouxihu farm life soil total nitrogen content in the three level;the content of available phosphorus in grade three the content of available potassium in level;level;the content of organic matter is at the three level.The total nitrogen content in the Anfeng study area was at the three level,the available phosphorus content was at the level of three,the content of available potassium was at the level of the level of two,and the content of organic matter was at the level of four.The total nitrogen and available phosphorus in soil in the study area were in the middle level,the available potassium was grade two,and the content of potassium was higher.An organic matter in Fengzhen area in the four level,the organic matter is a lack of consistent fertilization changes of soil nutrient elements with the District,or regional organic fertilizer supply.