Submitted to: Journal of Environmental Quality
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/1/2010
Publication Date: 3/1/2011
Citation: Maguire, R.O., Kleinman, P.J.A., Dell, C.J., Beegle, D.B., Brandt, R.C., Mcgrath, J.M., Ketterings, Q.M. 2011. Manure management in reduced tillage and grassland systems: A review. Journal of Environmental Quality. 40:292-301. Interpretive Summary: Managing land application of manures remains one of the most challenging aspects of livestock production. Technologies to apply manures to agricultural soils, and our understanding of how these technologies fit into reduced tillage systems, are rapidly evolving. This paper provides a comprehensive review of manure management in farming systems where tillage cannot be used to incorporate the manures, highlighting production and environmental concerns.
Technical Abstract: Managing manure in reduced tillage systems remains a major concern, because tillage has traditionally been used to incorporate manure. Surface applied manure that is not incorporated into soil provides inefficient delivery of manure nutrients to crops due to environmental losses of nutrients and serves as a major source of nuisance odors. An array of technologies exists to facilitate the incorporation of liquid manures into soil with restricted or minor soil disturbance, many of which are new: shallow disk injection; chisel injection; aeration infiltration; pressure injection. We summarize what is known about the performance of these technologies with respect to agronomic, soil and environmental variables. Compared with surface application of manures, injecting manure can decrease ammonia emissions, odors and nutrient losses in runoff. Soil aeration is less consistent in its benefits, but refining its method of use and timing relative to manure application may improve its effectiveness. Many technologies are now available and our findings point to significant trade-offs in various manure incorporation technologies and highlight context-specific trade-offs. Placing manure under the soil surface offers much promise to improve nitrogen use efficiency through less ammonia volatilization, reduced odors and decreased nutrient losses in runoff, relative to surface application. There are significant gaps in our knowledge as many of these technologies are new, and we propose the development of a standardized protocol for evaluating implements so that studies can more easily be compared.