Spatial variation and distribution of comprehensive productivity of cultivated land in different cultivation areas of Hebei Province

The comprehensive productivity of cultivated land, which is the deepening and extension of agricultural land classification and gradation, accurately accounts the absolute value of each gradient in cultivated land system. On the basis of agricultural land classification and gradation results, through investigating supplementary sampling points, the indexes of natural quality and land use were used to construct theoretical and realistic linear regression models for yield per unit, respectively, and practical productivity was obtained from statistical data. Four regions in each cultivation area of Hebei, Bazhou, Luancheng, Zhangbei and Zunhua from southeast to northwest, were selected to analyze spatial variation and distribution of comprehensive productivity of cultivated land. The results show that the total theoretical productivity is 2.52×109 kg, realistic productivity is 1.88×109 kg, and practical productivity is 1.44×109 kg; The productivity of per unit area, which is consistent with natural quality, appears to be as follows: Luancheng > Zunhua > Bazhou > Zhangbei; The spatial differentiation decided by productivity floating amplitude comes out to be Bazhou > Zunhua > Zhangbei > Luancheng. The method for calculating comprehensive productivity based on agricultural land classification and gradation is scientific, reasonable and feasible, which is an important approach and method to deepen the management of balance between quantity and quality of cultivated land resources.