Establishment of corn in rotation with alfalfa and rye: Influence of grazing, tillage, and herbicides

Integrating livestock into crop rotations offers alternatives for grazing a nd crop management, Grazing, tillage, and herbicides were evaluated in a ra ndomized block design with four replications for transition from alfalfa (M edicago sativa L,) to corn (Zea mays L,), For the control (T1), alfalfa was overseeded with rye (Secale cereale L,) in October, and corn was no-till e stablished in early May, For alternative treatments, alfalfa was grazed by cattle (Bos taurus) from July until October. Treatments were: T2, disking p rior to rye planting, grazing rye for 12.5 d prior to corn planting, with d icamba (3,6-dichloro-2-methoxybenzoic acid) applied after corn planting; T3 , no spring grazing,,vith glyphosate [N-(phosphonomethyl)glycine] applied b efore corn planting: T4, same as T3 plus grazing rye for 1.8 d in early spr ing; T5, autumn application of glyphosate to alfalfa before planting a rye- hairy vetch (Vicia villosa Roth) cover crop; and T6, autumn disking before planting rye-hairy vetch with no herbicides used. System T2 increased suppr ession of alfalfa and corn plant populations compared with shorter grazing periods. System T3 increased con plant populations compared with no spring grazing (T3; 3.5 vs. 3.0 plants m(-1)). Autumn disking (T6) generally provi ded less control of alfalfa than autumn application of glyphosate (T5), App lying glyphosate before corn planting (T3 and T4) improved corn populations and growth, compared with autumn glyphosate or disking (T5 and TG), and re sulted in corn forage yield (23 Mg ha(-1)) similar to conventional no-till establishment (T1; 22 Mg ha(-1)). Herbicides completely killed alfalfa, but gazing alfalfa and rye reduced alfalfa persistence, Grazing could provide benefits to corn production systems while providing forage for rattle.