Luis F. Rodríguez, Angela R. Green, Daniel W. Shike
While agricultural lands are often considered to be potential greenhouse gas (GHG) sinks, these lands also must meet growing human needs for food, feed, fiber, and energy. This presents a great opportunity for agricultural producers, especially in light of emerging ecosystem service markets and regulations. Meanwhile, agriculture often is singled out as a contributor to water and air pollution, including the generation of the powerful GHG, methane. These competing pressures pose a critical need to find innovative ways to balance agricultural productivity while managing environmental impacts, identified as the focus of this work. The goal of this proposed research is to develop decision support tools for livestock producers, particularly ruminant animal producers, to optimally manage economic and environmental system performance. Cattle production presents particular challenges in this regard, as methane produced from these systems can amount to 70% of all domestic methane emissions. However, improved management of crop and forage systems make it possible to offset a significant portion of GHGs by emission avoidance and terrestrial sequestration.
The investigators have devised three key tools that will lead to the development of models capable of decision support. First, we have demonstrated the capability to monitor in-field cattle movements utilizing global positioning systems (Figure 1). This will allow us to monitor the impacts cattle have on pasture, both positive and negative, thus providing the ability to better utilize the GHG sequestration capacity of pastures. Second, we have demonstrated the impact of management intensive rotational-grazing of cool season pastures, as well as strip-grazing crop residues, on cattle performance and economics in farm demonstration plots (Figure 2). This will allow us to design new practices to influence cattle behavior to encourage positive GHG balances, while improving system economics. Lastly, we have built expertise in monitoring impacts of crop management practices on soil carbon balances and fertility. This will allow more credible and permanent carbon sequestration.
The investigators seek to augment their capacity in several different ways. This work is significant because it will provide the fundamental knowledge and tools for the management of integrated agricultural systems (Figure 3). Additional sensors are being added to the cattle monitoring system, including accelerometers and radio frequency identification. This will allow the investigators to not only know the location of the cattle at any given time, but also assess the corresponding behavior. The investigators are developing and will utilize an indoor atmospheric flux chamber to measure methane emissions as impacted by forage-based and supplemented diets. This will allow the investigators to better understand the sources of methane generated by cattle. In parallel, the investigators are considering the impacts of grazing corn stover, rye, and turnips, as well as supplemental feeds like distillers dried grains with solubles on cattle performance. This will allow the investigators to ensure that economic performance is optimized. Finally, the investigators will model this information mathematically such that it can be utilized for decision-making.