Output response of non‐point source pollutants and its driving mechanisms of different arable land use patterns

Abstract

AbstractThe irrational use of arable land has caused increased nutrient loss and aggravated non‐point source (NPS) pollution. This natural process has a significant socioeconomic origin. However, because of the inconsistency between the simulation scale of NPS pollution mechanism models and the statistical calibre of socioeconomic factors, the quantitative expression of the relationship between socioeconomic development, arable land use, and NPS pollutant output needs further exploration. We improved the mechanism model using a flow accumulation algorithm to construct a measure of the NPS pollutant output response at the administrative region scale. The mediating effect test confirmed that socioeconomic factors such as labour transfer, farmland property rights, large‐scale operations, agricultural technological progress and risk aversion were also fundamental drivers that affected the NPS pollutant output by changing the arable land use form factors. The mediating drivers included endowment, landscape morphology, management system, planting mode and production capacity. The average total phosphorus concentrations per unit area in townships with various arable land use patterns were grain and economical crop extensive operations (0.83 mg/L); grain and economical crop scale operations (0.54 mg/L); grain, oil, and cotton scale operations (0.45 mg/L); and suburban compound operations (0.44 mg/L). We found that the degree of influence and path of each fundamental and mediating driver on NPS pollutant output concentrations showed clear differences between townships with different patterns, which were the primary reasons for the significant differences in NPS pollutant output responses.