Relay Intercropping Winter Cover Crop Effects on Spring Forage Potential of Sweet Maize Stover and Yearling Cattle Beef Performance

SIMPLE SUMMARY: Maize stover is used globally as winter feed for livestock but the nutritive value is low, requiring supplementation. Small landholders who grow sweet maize for the fresh produce market often also have cattle with little access to winter forage. Grazing cover crops with the stover can potentially increase the available nutritive value. Intercropping the cereal rye or hairy vetch into sweet maize approximately 65 days after planting (V7–9 sweet maize maturity) did not influence sweet maize stover biomass yield or nutritive value after winter. However, the crude protein concentration of hairy vetch was greater than rye, but digestibility was not different. Average daily gains by yearling cattle were similar when grazing maize–rye or maize–vetch. Producers with limited land resources should consider the timing of the spring planting of the primary crop, in this case, sweet maize, in relation to the initiation of grazing of winter cover crops to maximize utilization of the previous crop’s residue (stover) as well as the cover crop itself before the primary crop planting time. ABSTRACT: Small landholders who grow sweet maize for the fresh produce market often also have cattle with little access to winter forage. Grazing cover crops with sweet maize stover can potentially increase the available nutritive value. A 3-year randomized complete block study with three replicates at New Mexico State University’s Alcalde Sustainable Agriculture Science Center compared sweet maize (Zea mays var. rugosa) with sweet maize relay intercropped at the V7–9 stage with cereal rye (rye: Secale cereale L.) or hairy vetch (vetch: Vicia villosa Roth) for early spring grazing. Intercropping the rye or hairy vetch into sweet maize did not influence the sweet maize stover biomass yield or nutritive value after the winter. The dry matter (DM) yield and crude protein (CP) concentration of hairy vetch biomass was greater (p < 0.01) than rye biomass (1.46 vs. 2.94 Mg DM ha(−1) for rye and hairy vetch, respectively, and 145 vs. 193 g CP kg(−1) for rye and hairy vetch, respectively). Average daily gains by yearling cattle were not different when grazing maize–rye or maize–vetch. Producers should consider the spring planting timing of the primary crop and the initiation of grazing in the winter or the spring to maximize the utilization of the previous crop’s residue (stover), as well as the cover crop itself.