Spatial Pattern Of Soil Carbon And Nitrogen At The Core Area Of The Arid Valley In The Upper Minjiang River

This article studied different slope of soil organic matter and the spatial variability, distribution of total nitrogen content in the arid valley of the Minjiang River core area by using the traditional statistics and geostatistics theory. The main conclusions are as follows:(1) Semi shaded hillside soil organic matter and total nitrogen content was obviously higher than that in sunny slope and shady slope, it’s relevant to the moisture, temperature moderate of semi shaded hillside. The soil organic matter and total coefficient of variation in research area is between 10% and 100%, belonging to moderate variability. The soil C/N value is less than 25, and the soil organic matter is easy to translate. Semi shaded hillside relatively close to 25, and the soil fertility is higher, the carbon fixation role.(2) From the results of analysis of variation function, we can figure out that the effect of random factors on the shaded hillside soil carbon and nitrogen contents in the slope was higher than that of sunny slope; Half shade half sunny space of soil carbon and nitrogen of the total variation degree; Soil carbon and nitrogen in sunny slope showed a strong spatial auto correlation, and regional factors leading its spatial variability; Soil carbon and nitro-gen spatial slope on autocorrelation range maximum.(3) Variation of soil organic matter and total N content was showing a trend of theo-retical model, soil carbon and nitrogen of sunny slope belongs to the exponential model, slope belongs to spherical model and Gauss model, semi shaded hillside belongs to the ex-ponential model and the Gauss model. Isotropic analysis results show that the distribution of soil organic matter and total nitrogen is very regular in different directions.(4) Analysis of soil carbon and nitrogen fractal dimension D show that spatial distri-bution of soil carbon and nitrogen were once high, spatial variability was weak. The soil carbon and nitrogen spatial distribution on shady slope was once low, and the spatial varia-bility was strong.(5) The soil carbon and nitrogen of Moran’s I index analysis shows that, when the dis-tance is low, spatial relationship of soil carbon and nitrogen element of close, when the dis-tance increases close degree to reduce, differentially expressed stronger.(6) Using ordinary Kriging method of interpolation of soil organic matter and total ni- trogen, draw out the spatial distribution map, reflecting the distribution pattern of soil carbon and nitrogen in space. The spatial pattern of soil carbon and nitro-gen were taking block mainly sheet, the overall spatial variability became weaker; The spatial pattern of slope soil carbon and nitrogen in zonal distribution, the overall spatial variability became stronger; There are some differences between semi shaded hill-side spatial pattern of soil carbon and nitrogen.