Location: Livestock Nutrient Management Research
Project Number: 3090-31630-006-000-D
Project Type: In-House Appropriated
Start Date: Aug 31, 2021
End Date: Aug 30, 2026
Objective 1: Improve use of manure as a soil amendment and develop manure processing and treatment technologies to increase production value of manure and reduce manure constituent losses to the environment. Sub-objective 1A: Determine optimal rates of manure application on soil nutrient cycling, crop productivity, and soil health on the Southern Great Plains. Sub-objective 1B: Assess long-term (36-47 y) legacy effects of high rates of land-applied beef cattle manure on soil properties on the Southern Great Plains. Sub-objective 1C: Determine long- and short-term impact of cattle manure on soil parameters attributed to soil health. Objective 2: Quantify and develop practices to reduce emissions of greenhouse gases and other gases of concern to improve nutrient use efficiency and reduce the environmental footprint of beef and dairy production systems. Sub-objective 2A: Assess the impact of environmental conditions and management practices on emissions of GHG from open-lot beef and dairy cattle production systems. Sub-objective 2B: Assess the effect of land-applied manure on emissions of N2O and CH4 from soils. Sub-objective 2C: Quantify NH3 and organic N deposition downwind of beef feedyards and open-lot dairies on the SGP. Objective 3: Assess feed additives and alternative feedstocks to reduce enteric CH4 emission and improve cattle nutrient utilization. Sub-objective 3A: In vitro fermentation experiments can identify feed additives and ingredients that can reduce CH4 emissions in beef cattle. Sub-objective 3B: Assess the effects of feed additives and ingredients on enteric CH4 production and performance of live beef cattle. Sub-objective 3C: Design, construction, and testing of respiration chambers for quantification of enteric CH4 and N2O emissions from cattle.
Beef and dairy cattle provide vital human nutrition and important economic activity to a diverse U.S. population. Nevertheless, cattle production is linked to climate change and other environmental consequences. This research project will take a multidisciplinary approach to understand and mitigate environmental risks from cattle systems common to the semi-arid Southern Great Plains (SGP). Over six million beef cattle are finished annually in SGP open-lot feedyards, and over 400,000 cows are milked, with most being in open lots containing thousands of cows. We will quantify and improve prediction of greenhouse gas (GHG) emissions and ammonia deposition from cattle systems. Research will focus on the predominant agricultural GHGs, methane and nitrous oxide. Sources of these emissions include cattle (enteric emissions), pen surfaces at concentrated animal feeding operations (CAFOs), fertilized soils, and emissions from soils near CAFO that receive ammonia deposition. Dietary effects on enteric GHG emissions (i.e., emissions from ruminant digestion) will be examined at scales ranging from laboratory studies to entire pens of cattle. We will study specific feed additives for reducing emissions, including malted barley and red seaweed. We will apply cattle manure at varying rates to different forage crops to determine best management practices for the SGP. We will quantify changes in soil health parameters, including salinity, nutrient content and soil physical factors, after manure application or land use change. The research project will provide science-based information and technologies for producers, extension specialists, and regulators to protect air quality, manage feedyard and dairy manure, and ultimately enhance efficiency and sustainability of cattle production.