Location: Plant Science ResearchTitle: Crop and cattle production responses to tillage and cover crop management in an integrated crop-livestock system in the southeastern USA Author
Submitted to: European Journal of Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2013
Publication Date: 5/22/2014
Citation: Franzluebbers, A.J., Stuedemann, J.A. 2014. Crop and cattle production responses to tillage and cover crop management in an integrated crop-livestock system in the southeastern USA. European Journal of Agronomy. 57:62-70. Interpretive Summary: Transformative cropping systems are needed in the southeastern USA to improve production and avoid environmental deterioration. A scientist at the Plant Science Research Unit in Raleigh, North Carolina teamed with a former scientist in USDA-Agricultural Research Service from Watkinsville, Georgia to evaluate the effects of cover crop choice, cover crop management, and tillage management on crop and animal production characteristics. Severe drought limited summer crop yields. Cover crop choice, whether unfertilized legume-grass mixture or fertilized grass mixture, had little effect on production responses. Whether cover crops were grazed by cattle or not had small negative effects on summer crop yield responses, but the large gain in production from suckling calves overcame lost crop production. Corn and soybean responded positively to deployment of no tillage management compared with conventional tillage. Management of crops with no tillage was found to be a key tool in raising the productivity of integrated crop-livestock systems for the southeastern USA. Further developing integrated crop-livestock systems will be important for transforming agriculture in the southeastern USA towards greater and more sustainable production.
Technical 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. Grazing of winter cover crops added a stable component to production. No-tillage management had large positive effects on corn grain (95 vs 252 g m-2 under CT and NT, respectively) and stover (305 vs 385 g m-2) production, as well as on soybean grain (147 vs 219 g m-2) and stover (253 vs 375 g m-2) production, but little overall effect on winter wheat grain (292 g m-2) and stover (401 g m-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.