Study On The Forecasting Mehtod Of Grain Potential Productivity

Study on grain potential productivity is important for a country to crop production planning, population controling, natural resources utilization and environmental protection. Traditional potential grain productivity estimated on the basis of light and thermal resources generally is higher than the actual level and requires so many parameters that it is rather difficult to scientifically determine. In addition, the results of prediction provide little guidance for grain production, import and export planning as well as prevention and reduction of disasters. The results are as follow:(1) The potential grain yield is redefined in this article as yield of a certain crop under multi-year average climate conditions and technology imputs of that time.(2) Put forward the theory motivating force of science and technology of potential grain productivity.(3) Prediction methods applicable to different conditions have been set up, such as modeling n value determination method, dynamic n value determination method during year-by-year prediction, prediction method for occurrence of point of inflection in yield tendency, micro tendency rectification method, and macro tendency prediction plus micro tendency rectification method, which are integrated into a systematic prediction method.The proposed prediction theory and the established systematic prediction method can be applied as the theoretical and methodological foundation for potential grain productivity or even yield estimation in China. They can hopefully help to set up the national technical platform for information of potential grain productivity and yield estimation and become decision-making bases and research tools for government, business and researchers. They can also be applied to the prediction of other similar systems (systems with tendency-oriented variables and fluctuating variables), highly promising for a widespread application.