PHOSPHORUS RATE AND PLACEMENT METHODS WITH DOUBLE ROW RAISED BEDS

Abstract

Corn planted to originally acidic grassland soils with a low phosphorus (P) content and fertilized at normal rates produced low yields. A factorial study was designed with three application methods (banded, broadcast, tilled) at four rates (34, 67, 101, 134 kg/ha) P2O5. Sweet corn (Zea mays (L.) was planted in double rows on raised beds (0.9 m wide, 1.8 m centers) with 30 cm spacing in and between rows. Most yield parameters increased linearly with increasing rates of P. Banded P produced best yields, but growth was variable between the two double rows per bed. In a second study, P2O5 ranging from 0 to 403 kg/ha was applied by conventional methods. There was a positive response of most yield parameters to increasing rates of P. In a third study, soil plugs (2 cm diam., 10 cm depth) were removed 5 cm to the side of each plant. Rates of P2O5 ranging from 0 to 202 kg/ha were placed in the plugs. Yield responded positively to increasing rates of P. P applied in the plugs produced yield responses similar to P applied conventionally.