Economic benefit analysis of variable-rate fertilization technology in maize (Zea mays) field based on partial budget analysis method

Abstract: Precision agriculture is a modern agricultural technique which helps improve the yield and quality of crops, increase economic returns and reduce the pollution in agricultural ecological environment. In China, the effectiveness and economic benefits of applying precision agriculture technologies are not yet clear, which is an important factor that may hinder the popularization and application of precision agriculture technologies, such as variable-rate fertilizer application. Before changing from one production method to another, the farmer considers many factors, such as additional costs, and additional income resulting from the change. In this research, we aimed to estimate the effect on net benefit of changing from unified fertilizer application to variable rate fertilizer application. Partial budget was used to assess the costs and benefits associated with this specific change in a maize farm, which was based on a unit so data were collected from one large maize farm in the northeast of China. Field experiments were carried out in 2015 at Zhaoguang farm in Heilongjiang province, a typical large farm of northeast China. In this study, two fertilization treatments were included: 1) uniform nitrogen fertilization (CK), 12 hm2 in area, 2) variable rate nitrogen fertilization (VF), 6.67 hm2 in area. In the VF treatment plot. Crop yield goal was set up, soil samples were taken from a 50 m×50 m grid, and Alkali-soluble soil nitrogen was used as available nitrogen during the growing season. Based on those, we generated a variable rate nitrogen fertilization prescription map for maize using ArcGIS. The fertilizer was applied to the farm land as the prescription by variable-rate fertilizer applicator. Other farmland management measures of these two experiment treatments were the same. The main results were: 1) maize yield was improved by 1.8% through the variable rate fertilization compared with the unified fertilization, and the nitrogen fertilizer application amount was decreased from 171.4 kg/hm2 to 138.12 kg/hm2, decreased by 19.4%. 2) Applying variable rate fertilization technique need investment 50.63 yuan per hm2 more than uniform fertilization, and the net return was 383.23 yuan per hm2 higher than uniform fertilization. The rate of return on the increased investment of change from unified fertilization to variable rate fertilization was 753%, much more than the minimum rate of return on agriculture investment (105%). 3) Suppose the subsidy for purchase variable rate fertilizer applicator was 30% of the purchase price, the annual depreciation of variable rate fertilizer applicator decreased from 70.95 yuan/year to 49.66 yuan/year. The rate of return on the increased investment of change from unified fertilization to variable rate fertilization increased to 1366% as the increased investment decreased to 29.61 yuan/year. In summary, the new technology should be feasible for farmers to accept according to the criteria for partial budget analysis. In addition, subsidy policy to purchasing variable rate fertilizer could increase the economic benefit of application of variable rate fertilization technology in large farms.