基于LESA体系的高标准基本农田建设时序研究

高标准基本农田建设地既要符合建设的内涵和要求,又要实际考虑研究区基础设施和社会经济条件.为了科学合理地进行综合评价和时序研究,论文以沈阳市沈北新区为例,借鉴美国土地评价与立地分析(LESA)思想,根据自身限制条件和耕地质量更新成果进行综合质量评价,自然质量因素选取有机质含量及土壤质地等,立地条件因素从基础设施条件和社会经济条件两方面选取,基础设施条件主要选取灌溉保证率,排水条件等,社会经济条件主要选取单位面积投入及农业技术人员投入等.在评价结果的基础上采用自然断点法与K-均值聚类法相结合的方法划分建设时序.结果表明,近期建设区占研究区的43.95%,主要进行农田基础设施建设,致力建设设施完备,高产稳产的现代化农田;中期建设区占研究区的25.01%,以提升自然质量为主导建设方向,建立协调发展的高产农田;远期建设区占研究区的31.04%,应全面展开建设,以提升农田综合质量达到高标准基本农田建设标准.

Study on Time Sequence of High-standard Prime Farmland Based on LESA

Large-scale, high quality capital farmland construction is regarded as one of great national strategies in China. The paper makes full use of agricultural land classification results and is based on stable background of the high-standard prime farmland construction. As the material basis for the development of modern agriculture, well-facilitated capital farmland is the key to ensure food safety in China which improves the comprehensive productivity of cultivated land and agricultural production condition. The construction, effective management and efficient utilization of well-facilitated capital farmland have great significance for food security and modern agriculture. The time sequence of high-standard prime farmland construc-tion were determined by the integrated quality and limiting factors. Taking Shenbei city in Liaoning province as an example, based on the actual situation of Shenbei, the farmland quality and site condition were evaluated separately with LESA method. First of all, we established land evaluation system mainly about soil fertility. The key indicators are soil texture, depth of obstacle layer, content of soil organic and profile configuration. Expert evaluating method was applied to calculate the weight. We established site evaluation system reflecting the external condition. The evaluation is divided into two parts, farm infrastructure and socio-economic conditions. Then indicators were used to calculate the correlation coefficient, and quality score of each part was obtained. Finally the system of farmland evaluation and site assessment was established. According to the definition of quality facilities in capital farmland, capital farmland, which is presently in good condition or can be transformed into good condition in the future, are quality facilities. They can be divided into three kinds of construction zones. The capital farmlands with the highest ranking were those which can achieve the construction standard very soon through slight improvement. They belong to short-term construction zone. Those capital farmlands have the potential to become high quality farmland by improving the limiting factors belong to mid-term construction zone. Some capital farmlands having more limiting factors belong to long-term construction zone. According to different regional chara-cteristics, quality facilities in farmland construction should be carried out differently. Regions strategies that can improve the present limiting factors should be carried out first. Short-term construction zone of the study area accounts for 43.95%. The construction of short-term zone is targeted at agricultural infrastructure construction to build well facilitated, high quality and stable modern farmland. Mid-term construction zone of the study area accounts for 25.01%. The leading construction for mid-term zone is improving natural quality to establish coordi-nated and productive farmland. Long-term construction zone of the study area accounts for 31.04%, being in the worst socio-economic conditions. It is under high pressure of urbaniza-tion, so the attention should be focused on the balance between urbanization and agriculture when constructing quality facilities. In order to improve the overall condition of farmland, the construction should be in full swing to achieve high standards of prime farmland construction.