Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2011
Publication Date: 6/15/2011
Citation: Powell, J.M., Broderick, G.A. 2011. Trans-disciplinary soil science research: impacts of dairy nutrition on manure chemistry and the environment. Soil Science Society of America Journal. 40:907-914. DOI:10.2134/jeq2010.0492.
Interpretive Summary: Over the past decade or so, legislation has been enacted to control manure management and gaseous emissions from concentrated animal feeding operations. To address an immediate need for information and practices that would assist dairy producers in their compliance with new environmental regulations, trans-disciplinary dairy nutrition-soil science research was initiated to determine relationships between dairy cow rations, milk production, manure chemistry and environmental outcomes of dairy production. This paper describes key approaches and findings to this research to elucidate the role of soil science in solving problems outside traditional soil science research areas.
Technical Abstract: The on-going trend of consolidation and intensification of animal agriculture requires a greater dependence on purchased feed. Larger livestock farms and more imported feed can result in the excretion of manure nutrients that may surpass the recycling capacity of local land, air, and water resources. In response to these new environmental threats, legislation was enacted to control manure management and gaseous emissions from concentrated animal feeding operations(CAFOs). This paper provides an overview of nutrient cycling processes on dairy farms, and describes key trans-disciplinary dairy nutrition-soil science research findings, including how dairy rations could be modified to not only satisfy the nutritional requirements of healthy, high producing cows, but also produce manure less susceptible to environmental loss. Unnecessary mineral phosphorus (P) supplements were found to be excreted entirely in manure, which increased cropland area needed for compliance with manure spreading regulations, increased soil test P levels, and P loss in runoff from soil surfaces after manure application. Feeding crude protein (CP) above recommended levels and feeding forages high in degradable CP concentrations increases the excretion of N in urine and subsequent ammonia N loss after manure land application. Ration CP and type of forage fed to dairy cows also impacts ammonia N emission and manure N availability to crops. Three main ingredients to successful trans-disciplinary dairy nutrition-soil science research are an immediate and clear need for the information, a willingness and ability of scientists and stakeholders to collaborate, and funding.