Time variation characteristics of agricultural green development indexes in Lishu County, Jilin Province

As an advanced agricultural production county in China, Lishu County in Jilin Province has always been at the forefront of green agricultural development; this study took it as a typical case. Through the established indicators system of Chinese agricultural green development, combined with the nutrient flows in food chain, environment and resources use (NUFER) model, it analyzed the characteristics and change rules of agricultural green development indicators in terms of social economy, food production, and ecological environment, from 1994 to 2019, in Lishu County. The driving and restricting factors of county agricultural green development in Jilin Province were further explored. The results showed that the overall level of agricultural green development in Lishu County has improved steadily from 1994 to 2019, with the number proportion of indicators of gradeⅠ and gradeⅡ decreasing from 47% to 23%, and the number proportion of indicators of gradeⅢ and gradeⅣ increasing from 22% to 47%. In terms of social economy, the per capita comprehensive agricultural input and the per capita disposable income of rural residents have increased annually, and the per capita protein intake and the proportion of animal protein production have also improved, both reaching a grade Ⅳ level. Although the power of agricultural mechanization has shown an increasing trend, it is still at levelⅠ and needs to be improved. In terms of food production, the energy consumption per unit agricultural output value and the fertilizer phosphorus absorption utilization in farmland have been at level Ⅳ for many years; however, the comprehensive nitrogen use efficiency of livestock and poultry nitrogen has always been at a low level. The input of pesticides and fertilizer nitrogen reached levelⅢ in 2019; however, it did not increase continuously during the process, which was greatly affected by the years. In terms of the ecological environment, nitrogen emissions, nitrogen surplus, and environmental losses per unit cultivated land area due to nitrogen inputs all showed an improving trend from 1994 to 2019. However, the comprehensive utilization rate of livestock manure and the livestock and poultry carrying capacity per unit area was still at grade I, which meant that the development of the livestock industry still faces great challenges in Lishu County. Above all, the underutilization of resources, the environmental pollution, and ecological damage was caused by a single plantation structure, low yield of high-quality agricultural products, high input of pesticides and chemical fertilizers, and unstable numbers of livestock. It is therefore urgent to develop and utilize black land resources reasonably, to vigorously promote testing soil for formulated fertilization, improve conservational tillage and other excellent agricultural technologies, solve the contradiction between supply and demand of high-quality agricultural products, reduce damage to the ecological environment, and comprehensively promote the green development of agriculture in Jilin Province.