| Abstrakt: |
Tall fescuegrass (Festuca arundinacea) was seeded in Cecil sandy loam for 5 years in separate plots. Established fescuegrass plots were plowed and planted to corn during the same period. In 1968 both areas were plowed and planted uniformly to corn (Zea mays). Total N, carbon, organic residues, bulk density, and aggregation were determined on the soils of both areas. Soils from both areas were planted to sudax in the greenhouse. Yields increased from 2,728 kg/ha for continuous corn to 5,940 kg/ha for corn following 5 years of fescuegrass. After destruction of sod, corn yield decreased in 5 years from 5,018 kg/ha to 3,205 kg/ha. Sudax yields showed similar trends. Topsoil N increased from .047% to .088% as result of grass, and decreased from .078% to .054% as result of turning the grass. Soil carbon showed similar relationships. Soil bulk density and aggregation were not significantly affected by treatments. It was concluded that nonsymbiotic N fixation accounted for part of the nitrogen increase in fescuegrass sod and nitrogen conservation the remainder. |
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