Application of Soil and Water Assessment Tool (SWAT) to evaluate the fates of nitrogenous fertilizer in subtropical mountainous watershed tea farms
Journal
Environmental Monitoring and Assessment
Journal Volume
194
Journal Issue
3
Date Issued
2022
Author(s)
Abstract
Extensive nutrient loss is one of the most challenging issues faced by agricultural production regions worldwide. However, diffuse pollution in the subtropical mountainous watersheds is rarely simulated. A watershed model with regional parameter values is essential for watershed management. In this study, SWAT, one of the most popular models was applied to simulate daily discharge (years of 2008–2014), NO3-N flux (2012–2014), and tea yield (2012–2014) in the Ping-Lin watershed (PLW) of Taiwan, as well as to test the effectiveness of a modified fertilization strategy. The results demonstrated that SWAT was capable of simulating daily discharge variation, daily riverine NO3-N flux, and tea yield in the PLW. NO3-N yield of the tea farm (47 kg/ha/yr) was 9 times higher than that of the forest (5.1 kg/ha/yr). A significant proportion (~ 50%) of the input nitrogen (including dry/wet deposition and fertilizer) infiltrated into the soil, resulting in a poor fertilizer uptake efficiency of the tea tree. It was demonstrated that the modified fertilization strategy (apply fertilizer in small rainfall event, i.e., daily rainfall < 20 mm/day, and not in a single day) could increase the nitrogen uptake and harvest yield of the tea tree by 14% and 4%, respectively, with a 10% reduction in nitrogen input. Furthermore, this strategy significantly reduced the nitrogen yields from surface flow (75%), lateral flow (36%), percolation (50%), and groundwater (48%). A popular model with verified parameter values could help in developing a win–win strategy for both farmers and regulators, thus realizing the goals of sustainable agricultural practices. © 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
Subjects
Diffuse pollution; Fertilization strategy; Nitrate flux; Sustainable agricultural practices; Taiwan
Other Subjects
Forestry; Groundwater; Nitrogen fertilizers; Rain; Soil conservation; Solvents; Tropics; Water conservation; Water management; Water pollution; Agricultural practices; Diffuse pollution; Fertilisation; Fertilization strategy; Nitrate fluxes; Soil and Water assessment tools; Sustainable agricultural; Sustainable agricultural practice; Taiwan; Tea farm; Watersheds; ground water; nitrate; nitrogen; fertilizer; nitric acid derivative; nitrogen; water; agricultural practice; agricultural production; environmental fate; fertilizer; nitrate; soil and water assessment tool; tea; water pollution; watershed; agricultural land; Article; flow; forest; harvest; mountain; Soil and Water Assessment Tool model; soil fertilization; soil pollution; Taiwan; tea; tropics; watershed; agriculture; environmental monitoring; soil; Taiwan; Agriculture; Environmental Monitoring; Farms; Fertilizers; Nitrates; Nitrogen; Soil; Tea; Water
Type
journal article