A sustainable agricultural development assessment method and a case study in China based on euclidean distance theory

Based on the standardized Euclidean distance method, an evaluation theory for sustainable agricultural development was constructed, which includes a sustainable agricultural development model, an evaluation function model, a sustainable agricultural development exponent (SADE), a rank of the sustainable agricultural development, an index frame of the sustainable agricultural development, a goal system, and a zero system. Data from Zhenyuan County of Gansu province (ZYC) between 2000 and 2012 was used as a case study of the theory. The SADE of ZYC was [0.34, 0.90], and the agriculture system exhibited low sustainability from 2000 to 2003, mid sustainability from 2004 to 2007, and high sustainability from 2008 to 2012. The results explained the actual ZYC situation, and showed that the Euclidean distance method of sustainable agricultural development is feasible. The innovativeness and merits of the method include: (1) reliable methodology, (2) construction using goal and zero systems, which serve as reference systems of sustainable agricultural development and allow control of the evaluation, and (3) index weights embedded in the evaluation function, which prevents errors or mistakes in the expert scoring method and prevents the reassignment of index weights due to adding or subtracting indicators. The main reasons that the SADE increased in ZYC include suitable chemical fertilization and pesticide application, enhancement of conservation farming areas, soil testing and fertilizer-formulated areas, and drinking water security in rural and non-disaster crop areas. The main problems with increasing the SADE in ZYC include straw application and low farmer income, both of which should be increased.