By means of data review and causality analysis, this paper studies the progress of supplementary quantity and quality of arable lands converted by grade, indicating that it develops through policy proposal, base work and tentative practice. The future shall be focused on its continuity and technical optimization. Now it is appropriate to carry out the supplementary quantity and quality of arable lands converted by grade.

This paper comprehensively analyzes the insufficiencies in protecting and planning the basic farmlands, presents some views regarding the planning system, adjustment principles and controlled partition in the new general land utilization planning. Our study indicates that every national-, provincial-, municipal-, and town-level plannings shall embody the basic farmland layouts which can not be decreased in the mean levels during adjustment. The controlled partition can be classified into two types, the basic farmland protection zone and basic farmland dense zone. Rational farmland layouts and controlled partition are a key means to maintain the scientificity and practicability of planning.

Check of productive capacity of farmlands is an extension of graduation. The farmland productive capacity includes three levels, theoretic productive capacity, feasible productive capacity and actual productive capacity. This paper, by establishing some functions between theoretic unit production of standard crop and natural quality of farmland graduation, and between feasible unit production of standard crop and utilization index, verifies the theoretic unit production, feasible unit production, and based on this, the regional theoretic unit production, regional feasible unit production. The actual productive capacity of farmlands is verified mainly according to the unit production of specified crops in area. Taking a case study on Kaifeng county, Henan province, this paper verifies the productive capacity of farmlands and discusses some related technical questions.