| With the promotion of new rural communities construction and the rapid development of the urbanization, the policy of Rural land transfer push the decentralized management of fields forward to big scale management. What about the different influence to the soil nutrients spatial variability of the decentralized management and big scale management? The research before did not mention that. But it is very important to understand the future of the precision agriculture and the agricultural area source pollution control. Most rural land of the irrigation-silted soil fields in Yinchuan are under the decentralized managements of the peasants, but some land are under the big scale managements of the state farm. So, taking the irrigation-silted soil fields in Yinchuan as a research example is very typical and very representative to compare the different influence of the different managements. By adopting the combinative methods of classical statistics and geostatistics, we utilize the software of SPSS 17.0, professional GS+7.0 and ArcGIS9.0(the model of Geostatistical Analyst) to investigate the content level and spatial of the soil nutrients, autocorrelation and so on of the soil under different managements. The main conclusion of this comparing research is:1. Most soil nutrients of Lingwu experimental area are higher, the level of microelement Zn, Mn is very lower. The coefficient of variation of Zn and P are much bigger,46% and 51% respectively. The correlation of Mn and Cu is 0.71 and is the highest correlation elements, the correlation between Cu and Zn, Cu and Fe are also very high,0.65 and 0.59 respectively. The correlation among the microelements is very high. The geostatistics analysis shows that the homogenization of the soil of Lingwu area is very obvious, the spatial variation of most nutrients is weak, the random factors such as human activity play important role on the soil spatial variation. In this scale, the different distribution of soil doesn't produce large influence to the results. The nutrients composite index shows that the fertility level of Lingwu is very high. The geostastics analysis of the nutrients composite index shows the variability of it is very strong which is be contrary to that of single nutrient.2. The content of OM in soil of Wuzhong area is extreme low and the pH of the soil is alkaline. According to compare the amount of the samples which are lower than the critical value, it shows the content of N,P,K of Lingwu is higher than that of Wuzhong, but the content of microelements of the two districts is more or less the same. Be contrary to Lingwu area, the nugget effect of Wuzhong area is lower. It shows that the spatial variation of Wuzhong area is stronger than that of Lingwu area, the structural factors such as natural condition are leading role. The influence of the random factors is not obvious.3. According to the comparative analysis between the Lingwu district and the Wuzhong district, it shows that:(1) in terms of nutrients content the contents of N, P, K of Lingwu district are higher than that of Wuzhong area. In respect of microelements, there are not too much differences. The main reason is the fertilizing amount in Lingwu district is higher than Wuzhong district. (2) In terms of the spatial variability, spatial heterogeneity of Lingwu area is weaker than Wuzhong area, the random factors such as human activities of Lingwu are stronger than that of Wuzhong, the modern mechanized model and the big scale management should be the main reasons. The big scale management is a better way for the agriculture.
|
PDF Full Text Request