Nutrient Losses in Surface Runoff from a Native Prairie
1977
Timmons, D. R. | Holt, R. F.
Nutrient losses in surface runoff from a native prairie were determined for 5 years. The prairie, dominated by little bluestem (Andropogon scoparius Michx.), was on a Barnes loam soil in westcentral Minnesota. Snowmelt runoff accounted for 80% of the average annual runoff. After spring thaw, rainfall caused appreciable runoff (37% of annual) during 1 year only. Depending on chemical parameter, 63 to 88% of the average annual nutrient loads were transported by snowmelt runoff. Average annual total nitrogen (N) and total phosphorus (P) losses were 0.8 and 0.1 kg/ha, respectively, and organic N and organic (+ hydrolyzable) P comprised 68 and 82% of their respective annual losses. Average annual cation losses ranged from about 0.1 to 1.8 kg/ha and, except for 1 year, were in the order K > Ca> Mg > Na. Average weighted concentrations for all parameters were higher for rainfall runoff than for snowmelt runoff. Nutrient losses from native prairie represent natural levels for comparing the effects of different land uses on nutrient loads in surface runoff.
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