Research On Prediction And Evaluation For Comprehensive Benefits Of Poplar Agroforestry

In order to understand present situation and development potential of poplar agroforestry in Siyang County of Jiangsu Province, this study establishes a model for predicting and evaluating comprehensive benefits of poplar agroforestry by improving the Hartman Model, and applies this model to predict and analyse comprehensive benefits under five kinds of typical poplar agroforestry modes. Then this study sheds new light on better agroforestry modes through defining the forestry land comprehensive equivalent. On this basis, according to the trends of capital markets, this study simulates and analyses changes in different agroforestry modes’ comprehensive benefits when expected return on capital, price of inputs or price of outputs has changed. So as to enable farmers to make operation decisions from the perspective of maximizing their own interests. Finally, according to actual situation,this thesis sums up problems of poplar agroforestry in Siyang County, and puts forward countermeasures to promote sustainable development of poplar agroforestry.The results show that,(1) Agroforestry can ease up the contradiction between more people and less land and the contradiction between forestry and agriculture effectively to achieve sustainable development of forestry and agriculture. The study finds that if the10,000 hectares of pure forest land in Siyang County are suitable for the 5 kinds of agroforestry modes, at the year of maximum comprehensive benefit in each mode,the comprehensive benefit of poplar-mushroom multiple management mode is equivalent to the increase of 79,500 hectares of pure forest land, the comprehensive benefit of poplar-pickled cabbage multiple management mode is equivalent to the increase of 36,100 hectares of pure forest land, the comprehensive benefit of poplar-chicken multiple management mode is equivalent to the increase of 30,400 hectares of pure forest land, the comprehensive benefit of poplar-dandelion multiple management mode is equivalent to the increase of 25,100 hectares of pure forest land,and the comprehensive benefit of poplar-soybean-wheat multiple management mode is equivalent to the increase of 13,200 hectares of pure forest land. The land use effects of poplar agroforestry have important practical significance for Siyang County, whose per capita arable area is only 0.07 hectares.(2) Under baseline scenarios, all modes can be ranked in order of the land expected value, from largest to smallest: T4>T2>T5>T3>T1>T0(reference), or be ranked in order of the forestry land comprehensive equivalent, from largest tosmallest: T4>T2>T5>T3>T1, whether or not to consider opportunity cost of land.Thus it can be seen that, opportunity cost of land affects only different modes’ comprehensive benefits, without affecting selection of the optimum mode. For the land expected value and the forestry land comprehensive equivalent,poplar-mushroom multiple management mode(T4) is the best mode, next is poplar-pickled cabbage multiple management mode(T2), poplar-chicken multiple management mode(T5), poplar-dandelion multiple management mode(T3),poplar-soybean-wheat multiple management mode(T1) in order.(3) With predictions of different modes’ comprehensive benefits under baseline scenarios, sensitivity analysis of different modes’ comprehensive benefits under other situations and actual situation, considering from system’s profitability and stability, this paper argues that poplar-pickled cabbage multiple management mode(T2) has low costs and high profits, and it is less influenced by price changes than others.With profitability and stability, it can be considered as the best mode in this paper. However, operators should consider comprehensively and select carefully,according to subjective and objective factors such as market supply-demand and factors of production they have.(4) Aiming at bottleneck and deficiencies of poplar agroforestry in Siyang County, the paper proposes some suggestions. First, adhere to scientific planning and increase policy support. Second, strengthen comprehensive development of woodland and expand the scale of agroforestry. Third, raise funds from various aspects and promote infrastructure construction. Fourth, do depth and systematic research to improve the degree of information. Fifth, build innovative mechanisms and realize industrialization management to improve added value and market share of products. Sixth, grasp the point to promote surface and promote agroforestry widely. Meanwhile, strengthen science and technology support to accelerate the rapid development of poplar agroforestry.