Evaluation System For The Potentiality And Sustainability Of Crop Straw Resources

As a kind of by-product of agricultural production, crop straw is the largest renewable resource in the world. According to the statistics, there are about60～80million ton of crop straw resources produced each year in China, which ranks first in the world, accounting half of the total biomass resources. In recent years, along with the increasing amounts of straw resources, the rural energy structure improving, and the application of various types of alternative materials, crop straw resources formed a situation of regional, seasonal and structural excess. It not only caused a serious waste of resources, but also resulted in atmospheric and water pollution. Effective development and utilization of crop straw resources is related to efficient conversion of material and circulation of energy in agricultural production systems, and also related to sustainable development such as the fertility of soil and environmental safety and efficient use of renewable resources in agro-ecosystems. It is an important way to achieve the cycling agriculture and low-carbon economy. And it is significant to release the increasingly serious contradictions among resources shortage, environmental pollution and economic development.For the estimation and evaluation of the crop straw resources were not comprehensive, this author did investigation on the status of crop straw resources. On the basis of comprehensive analysis of affecting factors of crop straw resources, the paper established scientific and rational method system and index system of crop straw resources. Empirical study were taken based on the historical data from1990to2008and the survey data of crop straw resources in2009. Finally, recommendations to the development and utilization of crop straw resources were proposed form the reality of Jiangsu Province. The results of this thesis are as follow:(1) Back Propagation neural network (BP-ANN) and GM(1,1) methods were applied to evaluate the potential of crop straw resources with indexes of theoretical amounts, the per capita amounts and per planting area amounts. The paper also did research on the sustainability evaluation of crop straw resources for each utilization program by using the established evaluation system. The empirical results showed that the established prediction model and the evaluation system for the sustainability of crop straw resources development were reasonable and scientific, which had certain value of application.(2) The paper investigated the status of crop straw resources in Jiangsu. In2009, the theoretical amounts and the collected amounts of main straw resources were41.379million tons and33.742million tons respectively in Jiangsu Province. The collected amounts of rice and wheat straw accounted for more than70%, showing that rice and wheat straw would be the focus of development and utilization of crop straw resources in the future in Jiangsu. There were more than4million tons of crop straw resources in Yancheng, Huai’an, Xuzhou and Nantong, which had large resource density. They had large amounts of straw resources which were key areas of development and utilization of crop straw resources in the future in Jiangsu.(3) The paper defined the predictions of crop straw resources in Jiangsu. In the next five years, the theoretical amounts would be between39-41million tons. The development trend of theoretical amounts would be stable in Jiangsu Province while the trends of per capita amounts and per planting area amounts will decline. The results were consistent with the local development plan which would be useful for relevant studies in the future.(4) The paper defined the sustainability of crop straw resources development in Jiangsu. The sustainability of straw manure utilization program (3.11)> the straw industrial raw materials utilization program (2.81)> the straw feed utilization program (2.64)> the straw base utilization program (2.57)> the straw energy utilization program (2.42). The straw manure utilization program, the straw industrial raw materials utilization program, the straw feed utilization program and the straw base utilization program had weak sustainability, whose comprehensive evaluation scores of sustainable development were between2.5and3.5. But the straw energy utilization program had weak non-sustainability, whose comprehensive evaluation score of sustainable development was between1.5and2.5.