Transport and prediction of sulfate in agricultural runoff

Journal Article · · Journal of Environmental Quality; (United States)

DOI:https://doi.org/10.2134/jeq1991.00472425002000020013x· OSTI ID:5325866

Sharpley, A N; Smith, S J ^[1]; Jones, O R ^[2]; Berg, W A ^[3]; Coleman, G A ^[4]

---

1. USDA-ARS, Durant, OK (USA)
2. USDA-ARS, Bushland, TX (USA)
3. USDA-ARS, Woodward, OK (USA)
4. Southern Plains Watershed and Water Quality Lab., Chickasha, OK (USA)

The measurement and simulation of sulfate-S (SO{sub 4}{minus}S) mobility in agricultural watersheds is necessary to evaluate the effect of management practices on associated crop S deficiencies, enhanced leaching loss of nutrient cations, and acidification of percolation waters. The concentrations and amounts of SO{sub 4}{minus}S in runoff from six grassed and 13 cropped watersheds in the Southern Plains were, thus, measured over a 4 year period. Sulfate-S transport in runoff was predicted using an equation describing the kinetics of SO{sub 4}{minus}S desorption from soil and compared with measured values. No SO{sub 4}{minus}S was added to any of the watersheds directly as S fertilizer or indirectly in N or P fertilizer material. No difference (at 5% level) in SO{sub 4}{minus}S concentration in runoff from frassed (mean annual value of 12.6 mg L{sup {minus}1}) and cropped (mean annual value of 11.0 mg L{sup {minus}1}) watersheds was observed. Differences in amounts (0.2 - 18.9 kg ha{sup {minus}1} yr{sup {minus}1}) were a function of runoff volume as influenced by land management. A general trend of increasing SO{sub 4}{minus}S concentration in runoff with decreasing pH was observed, which may be a function of S dry deposition and soil and crop conditions. Measured and predicted SO{sub 4}{minus}S concentrations in runoff for individual events were not significantly different (at 5% level), with an average predictive standard error of 1.6 mg L{sup {minus}1} for all watersheds, representing 17% of the measured concentration. The equation may, thus, provide a predictive tool in agronomic and environmental studies of SO{sub 4}{minus}S movement in agricultural watersheds.

• OSTI ID: 5325866
• Journal Information: Journal of Environmental Quality; (United States), Journal Name: Journal of Environmental Quality; (United States) Vol. 20:2; ISSN JEVQA; ISSN 0047-2425
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
540320 -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
AGRICULTURE
CHEMISTRY
CROPS
DEPOSITION
DISSOLUTION
ELEMENTS
ENVIRONMENTAL IMPACTS
ENVIRONMENTAL TRANSPORT
FERTILIZERS
INDUSTRY
LEACHING
MASS TRANSFER
NONMETALS
OXYGEN COMPOUNDS
RUNOFF
SEPARATION PROCESSES
SOIL CHEMISTRY
SOILS
SULFATES
SULFUR
SULFUR COMPOUNDS
WATERSHEDS