Study On Spatio-temporal Variability And Definition Of Management Zones Of Soil Nutrients On Gis

The biggest characteristic of precision agriculture which compared to traditional agriculture is obtain the biggest resource saving and the best benefit of agricultural output through high-tech investment and management. However, traditional agricultural productivity has being based on field unit. In the same way, the variable values of soil properties were not equivalent in different time and in the same spatial position. And same quantities of agricultural materials were applied to the whole field at the certain zone. In response, it is important to fully understand the spatio-temporal variability of soil nutrient, define proper managerial units。Agriculture of Xinjiang BINGTUAN has the characteristics of wide farmland, high level mechanization, unionized management, similar weather in zone of every corps, and different spatial distribution of soil nutrition, conducive to the implementation of precision agriculture. The research of precise zone section for farmland that have multiple soil Attribution, can provide reference pattern for probe precision agriculture management mode to suit Xinjiang characteristic, as the basic unit of company govern by regiment. And provides basic information variable fertilization and soil precise management on scale farmland.In this study, conventional statistics, Geostatistics, the spatial analysis technique of geographic information system were used to analyze spatio-temporal variability of soil properties in the study area, based on which, to design the classify precise management zones. Some satisfied results were obtained as follows.(1)The study areas there are some soil nutrient spatial variability and temporal variation, however, the level of nutrients in different variations.Structure in space,1997, 2002 and 2007, soil organic matter and soil nutrients nugget value and base value of the ratio increased to varying degrees, by the strong spatial correlation weakening; Change process showed increased soil organic matter, AN and AK of the uniform spatial distribution of variables increased the scope of which is similar to the increase in large-scale variability within the reduced, And AP from the space-related significant decrease in the larger changes in spatial distribution. All of this shows that nearly 10 years of the study area resulted in the cultivation of soil organic matter and soil nutrients tend to weaken the structural variation, stochastic variation tend to strengthen.Structure in terms of time, the study area the spatial distribution of AK time stability of the best, followed by OM and AN, AP stability of the spatial distribution of the minimum of time. It can be said that the past 10 years, man-made farming measures, land use and farm management practices that affect soil nutrient variability among the many factors that an important factor.(2)Based on analyzing spatio-temporal variability of soil properties in the study area, to the company as the basic unit of Zoning, Fuzzy c-means clustering algorithm was used to delineate management zones. In order to determine the optimum fuzzy control parameters at the 148th Corps 6 group. Results, The optmium number of the classes and the fuzziness exponent were 4 and 1.7 respectively. The average confusion index was 0.29 in all management zones. Meanwhile, the cotton yield was chosen as the external variable. The average confusion index was low in all management zones. Thus, the overlapping of fuzzy classes at points was low and the spatial distribution of membership grades was unambiguous.