Sustainable strategies related to soil fertility, economic benefit, and environmental impact on pear orchards at the farmer scale in the Yangtze River Basin, China.

Abstract

Pears are an important income source in China, and unreasonable management practices have had a negative impact on the sustainability of pear orchards. However, multi-objective synergistic strategies are unclear on a farmer scale. In this study, we quantified indicators of soil fertility (soil organic matter (SOM)), environmental impact (global warming potentials (GWP)), and economic benefit (ratio of benefit and cost (BCR)) and analysed the synergetic strategies based on survey data from 230 smallholders in the Yangtze River Basin (Shanghai City, Chongqing City, Zhejiang province, and Jiangxi province). The average SOM, GWP, and BCR were 28.9 g kg-1, 17.3 t CO2-eq ha-1, and 3.63, respectively. Furthermore, optimised solutions using the Pareto multiple-objective optimisation model can reduce the GWP by 44.6% and improve the SOM and BCR by 34.4% and 43.9%, respectively, when fertiliser N rate and density are both decreased and the ratio of organic fertiliser application is increased compared to farmer management practices. The structural equation model indicated that planting density and fertiliser N rate can directly influence GWP and indirectly increase SOM and BCR; organic fertiliser application directly affects the GWP, SOM, and BCR. Our research provides a bottom-up approach based on the farmer scale, which can improve the sustainability of pear systems, and these findings can be used as guidelines for policymakers and pear orchard managers.