Study on Evaluation of Spatial Variability of Soil Nutrient on the Grain Crop Region of County

This paper took Huimin county for example analysis soil nutrient balance and spatial-temporal variability for more understanding spatial-temporal variability of soil nutrient on the grain crop region of county.The results showed that,nitrogen and phosphorus in soil were superabundant,and potassium balanced from 1985.There were three types of spatial variability of soil nutrient in Huimin county:①The spatial variability of exchangeable K was best described by exponential model,and the maximum correlative distance was 16.6 km.②The spatial variability of total N increased with increasing spatial distance.To some extent,there was tendency of them in spatial distribution.③The spatial variability of Olsen-P had no relation with spatial distance inside the sampling distance.Compared with spatial distribution of soil nutrient in 1984,a litter differences were observed to spatial distribution of total N and exchangeable K,and a large differences were observed to spatial distribution of Olsen-P.The character of spatial-temporal variability of soil nutrient was similar to soil nutrient balance.It indicated soil nutrient balance was important factor to result in the difference of spatial-temporal variability of soil nutrient.