Abstract

A study was initiated to determine the quantity of nutrients and sediment in runoff from conventional and no-till corn (Zea mays L.) watersheds. Runoff was collected with H-type flumes and Coshocton wheels. Parameters measured in runoff included NH₄⁺-N, NO₃⁻-N, total N, ortho-PO₄, total soluble P, total P, suspended sediment, and soluble solids.

There was a significant difference in total runoff between the conventional and no-till watersheds. Over nine times more runoff originated from the conventional-till watershed when compared with the no-till watershed in 1982. A large difference between the two watersheds in suspended sediment content was also observed. Yearly sediment losses of 370 and 9 kg ha⁻¹ from the conventional and no-till watersheds, respectively, were found for 1982. There was also a significant difference in the loss of soluble solids between the two watersheds. For 1982, there was over a 29-fold greater loss of soluble solids from the conventional-till watershed than from the no-till watershed.

Losses of NH₄⁺-N, NO₃⁻-N, and total N from each watershed were very low, although large differences were observed between the two watersheds. In 1980, 271, 638, and 1199 g ha⁻¹ of NH₄⁺-N, NO₃⁻-N, and total N, respectively, were lost from the conventional-till watershed, while 2, 47, and 87 g ha⁻¹, respectively, of the above parameters were lost from the no-till watershed.

The loss of all forms of P from each watershed was also very small. During 1982, 161 g ha⁻¹ of total P were lost from the conventional-till watershed while only 8 g ha⁻¹ were lost from the no-till watershed. The loss of ortho-PO₄ and total soluble P was not significantly different between the two tillage treatments.

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