Berseem clover seeding rate and harvest management effects on forage yields and nutrient uptake in a swine effluent spray field

Abstract

AbstractA 3‐year study was conducted on a Prentiss sandy loam near Pheba, Mississippi to determine optimum berseem clover (Trifolium alexandrinum L.) seeding rate (SR) for dry‐matter (DM) yield and nutrient uptake in an annual clover–perennial bermudagrass [Cynodon dactylon L. (Pers.)] sward, fertilized in April to October with swine effluent. Seed of annual berseem clover (cv. ‘Bigbee’) was drill‐seeded in October at 4, 8, 12, 16, 20 and 24 kg ha−1 and harvested either twice in April and May (spring) or once in May. Yield of clover harvested twice was less than that harvested once (5410 vs. 7566 kg ha−1), but N and P uptake were greater in the double‐harvest regime. Annual clover responses to SR were described by quadratic trends. Pooled across years and harvest regimes, the optimum SR for DM yield was 16·5 kg ha−1 and for P, Cu and Zn uptake, it was 15·7, 14·8 and 16·0 kg ha−1, respectively. Bermudagrass DM yield decreased linearly as SR increased by approximately 6·3 and 66·7 kg DM kg seed−1 in double‐ and single‐harvest regimes, respectively. For clover–bermudagrass, the optimum SR for DM yield was 14·0 kg ha−1, and for P, Cu, and Zn uptake, it was 15·1, 14·6 and 15·3 kg ha−1, respectively. A SR of 14·0–14·9 kg ha−1 and a first harvest of clover in April appeared to optimize hay yields and uptake of nutrients in clover–bermudagrass. Because bermudagrass N requirement is usually met by swine effluent irrigations, overseeding annual clover would chiefly satisfy producer needs for early forage production.