Effects of Knifed Vs. Broadcast Fertilizer Placement on Yield and Nutrient Uptake by Tall Fescue
1983
Lamond, R. E. | Moyer, J. L.
Field studies were conducted from 1979 to 1981 to evaluate two fertilizer application techniques for established tall fescue (Festuca arundinacea Schreb.). Fertilizer solutions were formulated from urea-ammonium nitrate solution (UAN, 28-0-0) and potassium tripolyphosphate (0-11-21) or ammonium polyphosphate (10-15-0) and potassium chloride (0-0-50) to supply various rates of N, P, and K. These fertilizer solutions were either surface-broadcast through flat fan-spray nozzles or injected (knifed) 15 to 20 cm deep behind shanks on 38-cm spacings. The knifed method could be called a subsurface band application that places the fertilizer directly in the root zone. In Experiment I, N was applied at 56, 112, and 168 kg per ha with or without 20 kg of P/ha and 37 kg K/ha. In Experiment II, rates were 13, 112, and 168 kg N/ha; 0 and 20 kg P/ha; and 0 and 37 kg K/ha. All experiments were conducted on Parsons silt loam soils (Mollic Albaqualf, fine, mixed, thermic) that tested low to medium in available P and K. Total yields and N concentrations of forage generally increased with N rates up to 168 kg N/ha. Phosphorus fertilization increased forage yields, P concentrations, and P uptake. Forage yields were not significantly increased by K fertilization, but on low-K soil, adding K tended to increase yields when N and P were supplied. Fertilization with K increased forage K concentrations, but had little influence on other forage constituents. Knifed fertilization was superior to broadcast applications of fertilizer and significantly increased forage yields, N content, N uptake, K uptake, and sometimes K concentrations and P uptake. The superiority of the knifed application was due mainly to better N utilization.
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