A method for calculating potential productivity of main crops in dry farming system as well as assessment of agricultural resources utilization in temperate zone, NortheastChina: A case study of Hailun County, Heilongjiang Province
东北温带旱作农业主要作物生产潜力及资源利用效率评价——以黑龙江海伦市为例

This paper combines PS123 model with ordinary methods into a comprehensive model to calculate the main crops potential productivity from 1999 to 2001 in Hailun County,so as to propose a more objective and scientific method to calculate crop potential productivity.The photosynthesis potential productivity(PPP) is calculated by the equation established by HUANG Bingwei.The temperature potential productivity(TPP) and climate potential productivity(CPP) are determined by PS123 model.And land potential productivity(LPP) is calculated by multiplying an effective coefficient,which is decided by AHP approach.At the same time,based on the productivity of different levels,agricultural resources utilization assessment model is also established which is composed of productivity loss value,contented index and utility ratio.By this way it can be found the main restricting resource factors and the restricting degree to achieve the purpose of appraising agricultural resources utilization efficiency comprehensively.The result shows that in natural resources temperature restricts productivity most,then moisture condition and soil fertility condition.If TPP is regarded as the highest productivity that can be realized,then the TPPs of maize,soybean and wheat are 11998,7068 and 8813kg/hm2,their resources use efficiencies are 51.0%,29.0% and 20.2%,there is still great potential on main crops in Hailun County.To improve the productivity,on the one hand,perfect farmland capital should be constructed,and fertilizer and water input should be performed to remedy the deficiency in the natural resources.On the other hand,the enthusiasm of peasants to agricultural production should be aroused,and their educational level should be improved for the easier adoption of new technology,fine seeds and the planting system and planting way should also be improved to higher resources utilization efficiency.At the same time,there still exists difference between crops in the need of agricultural resources.Following the characteristics of different crops to invest resources can distribute resources rationally to obtain higher product.