ARS | Publication request: Dairy Cattle Management Impacts Manure N Collection and Cycling Through Crops in Wisconsin, USA

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 20, 2009
Publication Date: February 23, 2009
Citation: Powell, J.M., Russelle, M.P. 2009. Dairy Cattle Management Impacts Manure N Collection and Cycling Through Crops in Wisconsin, USA. Agriculture, Ecosystems and Environment [electronic journal]. 131(2009):170-177.

Interpretive Summary: As energy and fertilizer prices continue to increase and regulations aim to limit ammonia emissions, livestock producers seek new ways to reduce manure management costs, enhance the fertilizer value of manure and reduce ammonia emissions from their farms. We compared two dairy herd management practices on manure collection and recycling through crops: corralling dairy cattle directly on cropland, and the conventional practice of barn manure collection and land application. After corralling, crops recovered 30 to 50% of applied manure nitrogen versus 22 to 35% for manure scraped and hauled from barns. Dairy farmers and their nutrient management consultants can use this information to devise herd management practices that conserve manure nitrogen thereby reducing costs of manure management, fertilizer and ammonia losses from their farms.

Technical Abstract: Escalating energy and fertilizer N prices and regulatory limits on ammonia emissions from livestock facilities require new methods that reduce manure management costs, enhance the fertilizer value of manure and reduce ammonia volatilization. We compared two dairy herd management practices on manure N capture and recycling through crops: the conventional practice of barn manure collection and land application, and corralling dairy cattle directly on cropland. Cattle were kept in a barn for two (B2) or four (B4) days and manure was hauled to fields, or cattle were corralled directly on cropland for two (C2) or four (C4) days. Two manure application seasons, spring-summer (SS) and fall-winter (FW) were used each of two years. Each season was followed by three-year crop rotations: SS by wheat-sudangrass-winter rye-corn-winter rye-corn, and FW followed by corn-winter rye-corn-winter rye-corn. Corralling resulted in 50 to 65% greater N applications than barn manure. In-barn N losses (% of excreted N, ExN) were greater from B4 (30%) than B2 (20%). Apparent N recovery of applied N (ANR) by wheat ranged from 13% to 25% at the lower (B2 and C2) application rates and 8% to 14% at the higher (B4 and C4) rates. First-year corn following the FW manure application season had ANR of 13 to 32% at the lower (B2 and C2) application rates and 9 to 20% of applied N at the higher (B4 and C4) rates. As a percent of ExN, ANR over the 3 yr rotation from C2 was 50%, B2 35%, C4 30% and B4 22%. Overall results demonstrated that corralling dairy cattle on cropland simplifies manure management, reduces ammonia loss, and improves urine N capture and recycling through crops.