Spatial Variation And Influential Factors Of Soil Organic Matter And Nitrogen In Agriculture Areas Of Baisha Village Based On Small-scale

This essay studies the spatial variation characteristics of soil organic matter (SOM) a nd nitrogen (N) at small scale in a agricultural zone of Taiping village of Shuangliu Cou nty. Based on field survey, chemical testing, and geostatistics, routine statistical analys is, buffer analysis by using the software ArcGIS9.0. It is also described the influenti al factors of SOM and N. Conclusion of the research can be described as follows:(1) In the study area, the content of SOM was 18.09±5.66g·kg-1, the content of soil total nitrogen (TN) was 1.05±0.36g·kg-1 and the content soil available nitrogen (AN) was 56.7±26.2mg·kg-1. The results indicated by single sample K-S test that th e content of SOM, AN agree with the lognormal normal distribution and the conte nt of TN agreed with the normal distribution. Coefficient of variation of SOM was 3 1.2%, TN was 73.3%, AN was 74.6% respectively. This proves discrete of SOM, TN, AN was higher than mean value, There is a great discrepancy in the observati on data.(2) It is shown significant anisotropy characteristics of SOM,TN,AN in the stud y area. The long-axis direction of SOM was North-South Azimuth 58.8° with major range 250.86 m and minor range 83.11m. The major direction of TN was about Nor th-South, azimuth 53.5° with major range 945.52 m and minor range 200.17m; The major direction of AN was about North-South, azimuth 39.8° with major range 945. 52 m and minor range 177.39m.In the other hand, SOM was 46.6% of random varia tion while TN was 73.3% of random variation and AN was 74.6% of random variati on. It proved that in the study area the random variation kept the larger proportion.(3) The content of SOM, TN, AN presented obvious spatial variation characteri stics. Generally, the content of SOM presented irregular lumps, circular distribution In this study,17.4% at the highest value (>22 g kg-1) regions of SOM were mainly d istributed in the flat area in the middle part of the study area. Meanwhile,7.6% at t he lowest value (<11 g kg-1) regions of SOM were mainly distributed in the rugged area in the eastern edge of the study area. The middle value regions of SOM was big gest area, up to 63.2% of the total area. At the other part, the content of TN presen ted irregular lumps distribution. The highest value (>1.2 g kg-1) regions of TN conten t were 9.6% of the total area. It is mainly distributed in the flat area in the middle part of the study area. The lowest value (<0.8 g kg-1) regions of TN content were 1 .8% of the total area. It is mainly distributed in the rugged area in the southern edg e and the northeast, southeast the part of the study area. The middle value regions of TN content were 43.6% of the total area. The middle parts of the study area where wa s the higher value regions of TN content in the radial spread around. The content of A N presented irregular lumps distribution. It was the same to TN. The highest value (> 65 mg kg-1) regions of AN content account for 11.5% of the total area. It were mainl y distributed in the flat area in middle part of the study area The lowest value (<4 5mg kg-1) regions of AN content account for 4.6% of the total area. It were mainly d istributed in the rugged area in the southern edge and the northeast, southeast the part of the study area. The middle value regions of TN content for 47.3% of the total are a. The middle part of study area where was the higher value regions of AN content in t he radial spread around.(4) Influence factors of the results can be concluded that there are several factor s influencing the soil nitrogen and organic matter in the study area. The results of va riance analysis indicated that different land-use type was the most significant effect fo r soil nitrogen and organic matter. The mean content of OM and TN have such charact eristic:Bamboo forest>pear>citrus>paddy field>loquat>plum>dry land>eucalypt us forest. The mean content of AN has different characteristic:Bamboo forest>pear >paddy field>citrus>loquat>plum>dry land>eucalyptus. Slope position was mos t significant effect for soil SOM. Slope position was more significant effect for soil TN. But. It was no significant effect for soil AN. The mean content of SOM and TN indicated that gully>flatland>platform>slope>top. The mean content of AN s howed that platform>gully>flatland>slope>top. But,pH、slope aspect slope gradi entheight have no significant effect. Correlation analysis showed that sand and cla y were the most significant effect for soil nitrogen and organic matter in soil granu lometric composition. The higher percentage of fine particle in Soil granulometric t he higher nutrient in the soil. Fertilization condition indicated that the soil nitrogen an d organic matter in the study area due to two parts. On the one hand, the farmers t o fertilize the soil while on the other hand, he farmers to fertilize the soil. other side, the study area straw returning to the field. The survey found significant positive co rrelation for both of them. Buffer analysis of residents and river buffer zone was sig nificant correlation for soil nitrogen and organic matter. It showed that the closer to the residential area, the higher of soil nitrogen, the closer to river buffer zone, the 1 ower of soil nitrogen.