Abstract
The effect of soil moisture level and phosphorus fertilization on corn (Zea mays L.) growth and P uptake was evaluated in a pot experiment under greenhouse conditions. Two soils, Lewisburg silt loam (fine, mixed, mesit, Typic Hapludalf) and Nipe clay (clayey, oxidic, isohyperthermic, Anionic Acrudox) were included in the study. The three moisture levels were M2 = field capacity, M2 = fluctuation between field capacity and 50% available water, and M3 = fluctuation between field capacity and permanent wilting point. The phosphorus treatments were P1 = 0 kg P/ha, P2=112 kg P/ha and P3 = 224 kg P/ha. Fresh and dry matter yield of corn plants grown on Lewisburg soil increased significantly with phosphorus fertilization. The field capacity treatment (M1) significantly outyielded the other two moisture treatments when 11 2 kg P/ha was applied. At 224 kg P/ha there was no significant difference in yield between M1 and M2 treatments, but both these treatments significantly outyielded the M3 treatment. Corn plants grown on Nipe soil did not respond to phosphorus or moisture treatments. Phosphorus applications to Lewisburg soil significantly increased phosphorus uptake by corn plants. Phosphorus uptake was 3.89, 21.60 and 42.73 mg/pot for 0, 112 and 224 kg P treatments, respectively. An increase in moisture stress decreased P uptake with M1, M2 and M3 yielding 27.88, 22.91 and 17.42 mg P/pot, respectively. Corn plants grown on Nipe soil showed a slight increase in P uptake with the application of 224 kg P/ha. but this increase was not significantly different from that of the other two P treatments. Nor did moisture stress affect P uptake. The lack of response of corn plants to P fertilization and moisture level of Nipe soil can be attributed to a high P fixing capacity of the soil.