ARS | Publication request: MANURE NITROGEN AVAILABILITY: DAIRY MANURE IN NORTHEAST AND CENTRAL U.S. SOILS

Submitted to: Biological Agriculture and Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 19, 2004
Publication Date: October 1, 2005
Citation: Honeycutt, C.W., Griffin, T.S., He, Z. 2005. Manure nitrogen availability: dairy manure in Northeast and Central U.S. soils. Biological Agriculture & Horticulture. v. 23. p. 199-214.

Interpretive Summary: Animal manures can provide nitrogen (N) for crop growth. However, excess N can degrade water quality. In order to use manure in an environmentally responsible manner, it is therefore necessary to understand how different factors control the availability of N from manure to crops. This study was conducted to evaluate the impacts of temperature, water regime, and selected soils on N availability from a liquid dairy manure. Temperature strongly influenced N availability over time, but a fluctuating water regime had no significant impact on manure-derived N. Nitrogen was less available from manure when it was applied to an Illinois soil than when applied to two Maine soils. Analysis of the soils indicted a higher microorganism population in the Illinois soil may have temporarily resulted in less available manure N. Because soil type had a dramatic impact on N availability, it is clear that additional soils with ranges in several physical, chemical, and biological properties should be further investigated for their relationships with manure N availability.

Technical Abstract: Accurate prediction of nitrogen (N) availability from manure is required for efficient utilization of this resource in crop production. This study was conducted to evaluate the impacts of temperature, water regime, and selected soils on N availability from a liquid dairy (Bos taurus) manure. Two Maine soils [Caribou sandy loam (fine-loamy, mixed, frigid Typic Haplorthod) and 'Newport' loam (unnamed variant of a Bangor silt loam; coarse-loamy, mixed, frigid Typic Haplorthod)] and an Illinois soil [Catlin silt loam (fine-silty, mixed, superactive, mesic Oxyaquic Arguidoll)] were incubated in the laboratory at 11, 18, and 25 C under constant (60% water filled pore space, WFPS) and fluctuating (60 to 30% WFPS) water regimes, with and without dairy manure in a factorial arrangement. Elevated NO3- levels reflected nitrification of NH4+ added in the manure, with little additional net mineralization of manure organic N. Temperature strongly influenced NO3- concentration over time, but this effect could be described with the thermal unit (degree day) concept. The fluctuating water regime had no significant impact on manure-derived NO3-. Changes in manure NO3- over thermal time could be described with a single exponential equation. However, less manure NO3- was observed in an Illinois soil than in two Maine soils. Separate particle size analysis and microbial community assessments indicate higher N immobilization potential in the Illinois soil. Because soil type had a dramatic impact on N availability, it is clear that additional soils with ranges in several physical, chemical, and biological properties should be further investigated for their relationships with manure N availability