Estimating riverine discharge of nitrogen from the South Korea by the mass balance approach

Abstract

The main objective of this research was to estimate the total mass of nitrogen discharged from various sources in Korea using the mass balance approach. Three different nitrogen mass balances were presented: (1) agricultural activities including raising crops and animal husbandry; (2) domestic activities, and (3) activities in forest and urban areas. These nitrogen balances were combined to estimate riverine discharge of nitrogen to the ocean in national scale. Nitrogen inputs include atmospheric deposition, biological nitrogen fixation, application of inorganic fertilizers/manures, animal feed/imported foodstuffs, and meat/fish. Nitrogen outputs include ammonia volatilization, denitrification, human/animal waste generation, crop/meat production, and riverine discharge to the ocean. The estimated total nitrogen input in Korea was 1,194.5 x 10(3) tons N/year. Nitrogen discharged into rivers was estimated as 408-422 x 10(3) tons N/year, of which 66-71% was diffuse in origin. The estimated diffuse discharges for land uses were estimated as 82 x 10(3) tons N/year from agricultural areas, 7 x 10(3) tons N/year from forestry and 75 x 10(3) tons N/year from urban and industrial areas.

Rational budgeting approach as a nutrient management tool for mixed crop-swine farms in Korea

“…Data obtained from farm census and lab estimation together with data collected from the published literature were used to construct the farm nutrient budgets [6,7,[9][10][11][12][13][14][15][16][17][18][19][20][21]. Nutrient fluxes were used to convert the different components of the nutrient budgets from their original reported unit to common units (Table 2).…”

“…Nutrient fluxes were used to convert the different components of the nutrient budgets from their original reported unit to common units (Table 2). Most of the fluxes used in this study were derived from the studies focused on Korea [6,7,[9][10][11][12][13][14]. Seed nutrient inputs fluxes were obtained from Kremer [15].…”

“…P lc = (AH×D l ×C P ×LC P ) (12) where N lc and P lc are the nutrient inputs from liquid compost (kg/yr); AH is the number of animals (head); D l is unit discharge coefficient for liquid fraction (kg/head/yr); C N and C P are the nutrient content in liquid fraction after separation (g/kg) and LC N and LC P are nutrient loading fluxes. v) Nutrient inputs from atmospheric deposition Values from previously published literature were used to estimate the N and P inputs from atmospheric deposition [9,11] and expressed as:…”

“…N den = N fert ×D fert +N com ×D com +TA×D agri (21) where N den is the nutrient output through denitrification (kg/yr); N fert is the nutrient input from chemical fertilizer (kg/yr); D fert is the denitrification coefficient for applied chemical fertilizer (%); N com is the nutrient input from compost (kg/yr); D com is the denitrification coefficient for applied compost (%); TA is the total arable land area (ha); D agri is the unit denitrification coefficient for arable land (kg/ha/yr). iv) Outputs in hydrologic export (leaching and runoff) Hydrologic export of nutrients was estimated in terms of leaching and runoff using fluxes derived from published literature [12][13][14]21] and expressed as:…”

Baseflow contribution to nitrates in an urban stream in Daejeon, Korea

“…Nitrogen, particularly in the form of nitrate, is the most common contaminant in aquifer systems (Freeze & Cherry 1979;Kim et al 2008). Because nitrates in drinking water cause Methmoglobinemia (blue baby syndrome) and cancer, US EPA promulgated nitrate concentration criteria for drinking water as 10 mg NO 2 3 -N/L and 1.0 mg NO 2 2 -N/L (Plumb 1998).…”