Location: Forage and Livestock Production Unit
Project Number: 6218-21610-001-00
Start Date: Dec 10, 2012
End Date: Dec 09, 2017
Livestock production systems in the Southern Great Plains are confronted with problems of limited and uncertain forage supply, increased climatic variability, and environmental degradation that threaten economic viability and system sustainability. This project will develop management practices and identify forage genotypes that are resilient under variable climate and will increase forage productivity and input use-efficiency on livestock farms at a range of scales. Commensurate with the scope of the location as a Long-Term Agroecosystem Research network site, we will initiate assessments of greenhouse gas (GHG) emissions and agricultural production under different livestock systems of the Southern Great Plains, including both native prairie and wheat pasture. Data from this study will be pooled with results from similar flux studies in the region to evaluate climate and environmental impacts on system response. To evaluate system resilience, over-utilized prairie ecological sites with a mix of native and introduced species indicative of good and poor condition mixed grass prairie will be used to evaluate the use of infrequent, high-intensity grazing on succession and diversity of forage species at the sites. The impact of prior encroachment of redcedar on old-field nutrient and seedbank reserves and consequent recovery of understory and grass species following removal of redcedar will be assessed. The use of legumes and grasses as green manure sources will be researched for summer (sorghum) and winter (wheat) grain crops to promote efficiency of N and water use. Nitrogen turnover and utilization by the subsequent crop will be assessed. Also, N-uptake and efficiency of utilization of cool-season annual and perennial species will be measured in greenhouse experiments to develop screening methods for plant germplasm. Improved management methods will be developed to fully utilize the genetic potential of new cultivars by enhancing establishment, yields, and utilization by livestock. To increase marketing options of livestock producers, we will determine appropriate forage resources for production of farm-finished beef, either on all forage or with limited grain inputs. Interactions of animal genetic type (frame score) and finishing system (forage or grain) will be assessed. Time-series data from ryegrass trials in four southern states in the last decade will serve as the basis for examining the possible importance of 5-day and 7-day summary weather statistics of the near-surface environment, and the variations of those statistics around decade-long averages, as a predictor for seasonal production. Plant breeding technologies will be used to develop improved cultivars of perennial C3 grasses, particularly fescue, that are more persistent under the regional climatic conditions, and are more water-use efficient. Basic molecular biology and biochemistry/physiology information will be developed that will improve plant breeding techniques and products.