Whole Farm Strategies to Balance Nitrogen and Minimize Ammonia Emission on Dairy Farms

Dr. Jennifer Becker is the PI. The purpose of the project is to (1) Conduct a whole-farm analysis of nitrogen (N) of a dairy farm by analyzing the feed, forage, milk urea nitrogen (MUN) and manure; (2) based on the N analyses, formulate a precision feeding regimen that was expected to reduce N excretion for the herd; and (3) organize and conduct a workshop and on-farm demonstrations to introduce a whole-farm strategy for conserving N and reducing ammonia emissions.

This extension project was a collaborative undertaking with Virginia Ishler (The Pennsylvania State University) and was funded by a grant from the USDA/Cooperative State Research, Education, and Extension Service (CSREES) Mid-Atlantic Regional Water Quality Program. It targeted agricultural consultants and producers and soil conservation district personnel. Nutritional strategies for reducing N excretion were presented and the use of straw covers and subsurface manure application to reduce ammonia emissions from manure storages and land-applied manure, respectively, were demonstrated.

Workshop participants were asked to complete a detailed pre-then-post questionnaire in which they were asked to rank their understanding and knowledge of 18 issues related to nutritional and manure management approaches for conserving N and reducing ammonia emissions. The rankings were done a scale of 1 to 5, with 1 indicating "no understanding" and 5 indicating "very thorough understanding". The participants indicated that they had a good understanding of the idea that "Efforts to balance nitrogen and reduce ammonia emissions should incorporate nutritional strategies and post-excretion manure management and are most effective when implemented as part of a whole farm management strategy" before the workshop and tour (Average score = 4.23). However, their responses to the remaining questions indicate that they were less certain about the most important mechanisms of nitrogen loss on the farm and the best opportunities and methods for reducing these losses.

The participants' understanding of specific management approaches for reducing N losses increased (generally by one point or more) as a result of the workshop and demonstrations. Thus, the workshop addressed an important knowledge gap. The participants were also asked to rank the extent to which they agreed with the following statement "I anticipate using the information provided by this speaker." using a scale of 1 to 5, with 5 = "Strongly Agree" and 1 = "Strongly Disagree". Every workshop participant assigned a score of 5 to each on-farm demonstration and the workshop presentations received scores ranging from 4 to 5. This indicates that the presentations and demonstrations were highly effective and provided the participants with practical information that they can put to use.

For more information, contact Dr. Jennifer Becker

Last updated: 02/7/2008