Crop and cattle production responses to tillage and cover crop management in an integrated crop–livestock system in the southeastern USA

Abstract

Integrated crop–livestock systems can help achieve greater environmental quality from disparate crop and livestock systems by recycling nutrients and taking advantage of synergies between systems. We investigated crop and animal production responses in integrated crop–livestock systems with two types of winter cover cropping (legume-derived N and inorganic fertilizer N), two types of tillage [conventional disk (CT) and no tillage (NT)], and whether cover crops were grazed by cow/calf pairs or not. The 13-ha field study was a modification of a previous factorial experiment with four replications on Ultisols in Georgia, USA. Recurring summer drought severely limited corn and soybean production during all three years. Type of cover crop had little influence and grazing of cover crops had minor influence on crop production characteristics. Cattle gain from grazing of winter cover crops added a stable component to production. No-tillage management had large positive effects on corn grain (95 vs. 252gm−2 under CT and NT, respectively) and stover (305 vs. 385gm−2) production, as well as on soybean grain (147 vs. 219gm−2) and stover (253 vs. 375gm−2) production, but little overall effect on winter wheat grain (292gm−2) and stover (401gm−2) production. Our results suggest that robust, diversified crop–livestock systems can be developed for impoverished soils of the southeastern USA, especially when managed under no tillage to control environmental quality and improve resistance of crops to drought.