Low‐disturbance restoration of degraded orchardgrass pastures: Forage productivity and soil C and N responses

Abstract Degraded cool‐season grass pastures pose a major challenge for sustainable forage production in the southeastern United States. Orchardgrass (OG; Dactylis glomerata L.), a widely used forage species, often exhibits poor persistence under suboptimal management and environmental stress, requiring restoration. Strategies that minimize soil disturbance while improving productivity and soil quality are needed to support long‐term pasture sustainability. This study evaluated six low‐disturbance strategies to restore OG pastures while preserving soil quality: (1) control (C‐OG), (2) synthetic N fertilization (OG+N; 67 kg N ha −1 ), (3) fall‐seeded alfalfa ( Medicago sativa L.) (FA), (4) spring‐seeded alfalfa (SA), (5) FA combined with crabgrass ( Digitaria sanguinalis L.; CG) (FA+CG), and (6) SA+CG. Treatments were applied from 2021 to 2022 in Spring Hill, TN, and evaluated for forage mass (FM), root biomass, and soil carbon (C) and nitrogen (N) concentrations. The OG‐N treatment produced the greatest FM (2390 kg DM ha −1 , where DM is dry matter), while C‐OG yielded the least (1927 kg DM ha −1 ). Alfalfa and alfalfa+CG treatments produced intermediate yields, averaging 2159 kg DM ha −1 , and did not differ among them. Root biomass declined over time across all treatments but was unaffected by restoration strategy. Soil C and N concentrations remained stable throughout the 2‐year period. These findings indicate that both N fertilization and legume‐grass mixtures can enhance productivity without soil disturbance or nutrient loss. Integrating alfalfa and CG into existing OG pastures offers a sustainable restoration approach that supports forage production while maintaining soil health.