Overseeding Common Bermudagrass with Cool‐Season Annuals to Increase Yield and Nitrogen and Phosphorus Uptake in a Hay Field Fertilized with Swine Effluent

Abstract

Haying common bermudagrass [Cynodon dactylon (L.) Pers.] is commonly used to manage field‐applied manure P in the southeastern USA but is limited to summer. This 3‐yr study was done to examine effects of extending the haying season by spring haying of fall‐overseeded annuals. Berseem clover (Trifolium alexandrinum L.), crimson clover (T. incarnatum L.), annual ryegrass (Lolium multiflorum L.), and wheat (Triticum aestivum L.) were compared with a nonoverseeded control. Dry matter (DM) yield and N and P uptake were measured in spring and summer hay on a Prentiss sandy loam (coarse‐loamy, siliceous, thermic Glossic Fragiudults, Ultisols) with high soil P following 6 yr of swine (Sus scrofa domesticus) effluent fertilization. Fall‐seeded plots were cut twice for spring hay and three times for summer hay. Spring hay of annual ryegrass (3.8–5.3 Mg ha−1 yr−1) yielded more DM than crimson clover (2.6–3.4 Mg ha−1 yr−1), wheat (2.5–3.3 Mg ha−1 yr−1), and the control (2.8–3.4 Mg ha−1 yr−1) every year but did not differ from berseem clover (3.1–4.6 Mg ha−1 yr−1) in 2 of 3 yr. Phosphorus uptake in spring hay of annual ryegrass and berseem clover (10–16 kg ha−1) was higher than crimson clover (8–12 kg ha−1), wheat (7–12 kg ha−1), and the control (6–11 kg ha−1). Nitrogen uptake in spring hay was higher in berseem clover (71–128 kg ha−1) than other treatments (43–80 kg ha−1), which did not differ. No differences occurred in summer hay (DM = 3.9–7.6 Mg ha−1, N = 72–191 kg ha−1, P = 13–21 kg ha−1). Overseeding common bermudagrass with berseem clover or annual ryegrass can improve hay yield and P removal.