Multifunctionality of annual forage crop mixtures for improved biomass, beef cattle diets, and soil health outcomes

Abstract

Cover crop mixtures (CCMs) can fit well into various agricultural production systems and have gained popularity among grain and livestock producers, as well as organic and market gardeners across western Canada, due to their potential to enhance forage production and soil health. This study evaluated nine CCM treatments, comprising seven multispecies combinations (two- to eight-way), monocultures of barley and oats, and three seeding rates (100%, 125%, and 150%). The results showed significant effects of CCM (p < 0.001), seeding rate (p < 0.001), and their interaction (p < 0.001) on forage yield and normalized difference vegetation index. The highest forage yield (10,084 kg ha⁻¹) was observed in a six-species mixture at 125% seeding rate. Nutritive value, such as crude protein (CP), total digestible nutrients (TDN), and fiber components, varied significantly across the mixtures. The eight-species mixture had the highest CP and acid detergent fiber (ADF), while the five-species mixture had the highest TDN. Principal component analysis revealed clear clustering of forage mixtures based on both nutritive and soil parameters, with key indicators including ADF, net energy for lactation, neutral detergent fiber, phosphorus, and soil organic matter. Notably, forage yield was not significantly correlated with any of the nutritive parameters. However, CP and relative feed quality were positively correlated with several quality indicators. These findings highlight the potential of optimized CCMs and seeding rates to enhance forage yield and quality while supporting soil health across diverse agroecosystems.