Surface‐Banded and Broadcast Dairy Manure Effects on Tall Fescue Yield and Nitrogen Uptake

Abstract

Efficient use of slurry manure nutrients for feeding forage crops on dairy farms is important. The main objective of this study was to compare the response of tall fescue (Festuca arundinacea Schreb.) to N in dairy (Bos taurus) slurry manure applied with a splash plate (broadcasting) or a drag‐shoe (surface banding) applicator, and broadcast mineral fertilizer, in spring, summer, and autumn. The effects of delayed application and band spacing were also examined. The study was conducted from 1994 to 1996 in southwestern British Columbia on a Monroe series soil described as a Eutrochrept (eluviated eutric Brunisol) of moderate to good drainage. Dairy slurry was applied at two rates (50 and 100 kg ha−1 of NH3–N) with splash plate or drag‐shoe applicators at the beginning of growth (early) or 7 to 10 d later (late). Ammonium nitrate fertilizer was broadcast at 0 to 125 kg N ha−1 in 25‐kg increments (only 50 and 100 kg ha−1 rates on the late date). Yield response to manure banded with the drag‐shoe applicator was similar to fertilizer applied at equivalent rates of mineral N. Yield response to splash‐plate‐applied manure was generally 0.5 to 1.0 Mg ha−1 lower than to fertilizer in summer and spring, but similar in autumn. Total N uptake was 15 to 20 kg ha−1 greater from drag‐shoe than from splash‐plate applied manure at high N application rate in spring and summer; differences in autumn were smaller. Treatment differences in total N concentration were small (at equivalent rates of applied mineral N). Apparent recovery of mineral N from manure was 20 to 30% greater with drag‐shoe than with splash plate application in summer and 18% greater for the early application in spring. Delaying manure application had little effect on yield, but increased tissue N concentrations in some treatments in summer and autumn. Nitrate concentrations were always similar or lower for manure than for fertilizer treatments. This study showed that manure applied with the drag‐shoe applicator produced consistent crop response similar to N fertilizer at equivalent rates of mineral N.