Study On The Methodology Of Land Evaluation For Digital Agriculture

Taking the unified management on any piece of land as the target the traditional agriculture ignores more or less the internal heterogeneity of land quality which exists in majority of land plots. In other words, in the traditional agriculture any farmland is managed as in even condition for crop growing at the regional scale or land plot scale, which will lead to blindly input such as excessively fertilizer or pesticide applying and cause cost increase and soil contamination. On the contrary, digital agriculture as the modern agriculture takes fully consideration of variability of land quality elements within a given land plot, such as soil fertility, soil texture, soil moisture, soil organic matter as well as weed, insect pest and disease. As a result, such activities as cultivation, fertilizer or pesticide applying, planting and irrigation can be controlled according to practical condition of the farmland, which will no doubt much beneficial to agriculture production. As one of the bases of digital agriculture, land evaluation is to assess precisely farmland quality. In the process of the land evaluation, except for land grading using quantified indices, other steps have to be taken in order to guide farmers in reasonable planting, irrigation, and fertilizer or pesticide applying. These steps include diagnosing richness of soil nutrient and moisture and making coordination among water, fertilizer, soil and air.In this thesis the present situation and development trend of land evaluation in China and abroad are presented, the methods and models used in land evaluation are analyzed, and the methods which can be used in the land evaluation for digital agriculture and in diagnosing the richness of soil nutrient and moisture are compared and analyzed. The emphasis of this thesis is put on dividing land units of the land evaluation for digital agriculture, establishing the evaluation norm system, and the process and methods for both integrated evaluation of land quality and the richness diagnosis of any single factor.The main content of this thesis is as follows: (1) The existed methods and models used in land evaluation are collected and reviewed, the present situation and development trend of land evaluation in China and abroad are introduced, and the methods to divide land unit and norm system of land evaluation are also presented and discussed; (2) According to the purpose of the land evaluation for digital agriculture the methods of dividing land unit and establishing the norm system of the land evaluation for digital agriculture are explored, and the methods of the integrated assessment on land quality and of diagnosing the richness of the factors affecting land quality are also discussed.The study of this thesis on the methodology of the land evaluation for digital agriculturehas new meanings since the process and the methods described in this thesis can be used for reference by other similar studies. In addition, it has a certain practical value because the methods can be used to guide land use and cultivation practice.