Effect of surface application of polyvinyl alcohol on phosphorus losses in runoff and on corn growth
1992
Marsh, M.H. | Groenevelt, P.H.
Phosphorus loading in surface water bodies due to runoff from cropland is a major concern with respect to water quality. Losses of water, soil, and different forms of P, from five runoff plots treated with polyvinyl alcohol (PVA), were compared to losses from five untreated plots. The plots were on a loam soil with 6.5 to 9.5% slopes. The effect of a single application of PVA was observed over 2 yr under natural rainfall. During the first year after application of PVA, runoff and soil losses were reduced by 56 and 80% respectively. Extractable P, total P, and dissolved molybdate-reactive P (DMRP) losses were reduced by 79, 75, and 64%, respectively. Corn (Zea mays L.) grain yield on the treated plots was 12% higher than on the control plots. All the above differences were statistically significant. During the second year, in which no tillage occurred and no PVA was applied, total P and DMRP losses were reduced by 42 and 40%, respectively, by the PVA treatment of the previous year. Although runoff and soil loss were lower for the treated plots, these differences were not significant at P = 0.05 (P values were 0.11 and 0.10, respectively).
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