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United States Department of Agriculture

Agricultural Research Service

Title: Nutrient Management Behavior on Wisconsin Dairy Farms

Authors
item Powell, J Mark
item Jackson-Smith, D. - UTAH STATE UNIVERSITY
item Mccrory, D. - UNIV-WISCONSIN-MADISON
item Saam, H. - UNIV-WISCONSIN-MADISON
item Mariola, M. - UNIV-WISCONSIN-MADISON

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 10, 2006
Publication Date: March 15, 2007
Citation: Powell, J.M., Jackson-Smith, D.B., Mccrory, D.F., Saam, H., Mariola, M. 2007. Nutrient Management Behavior on Wisconsin Dairy Farms. Agronomy Journal. 99:211-219.

Interpretive Summary: Little is known about when, where and how much dairy manure farmers apply to their fields and if application practices conform to recommendations and regulations. Thirty-three Wisconsin dairy farmers and a research team kept detailed records on fertilizer, manure, and legume nitrogen and phosphorus applications to cropland from October 2003 through September 2004. Overall study results indicated that farmers were integrating fertilizer-manure-legume management much more than previously thought, that relatively few farms would have to change current practices to adhere to the proposed Wisconsin Code 590 Nutrient Management Standard, and that a relatively small proportion of farmers were employing nutrient management practices that may be detrimental to water quality. Policy makers are using this information to target cost-sharing programs to the small cropland area types and farmer practices where water quality improvements can be made.

Technical Abstract: Nutrient management plans for livestock operations should account for rates and timing of manure application to cropland, as well as how manure is integrated with other nutrient sources. Little is known, however, about actual farmer nutrient management practices and what changes may be needed for farmers to adhere to nutrient management regulations. Detailed records were kept on fertilizer, manure, and legume nitrogen (N) and phosphorus (P) applications on thirty-three representative Wisconsin dairy farms during the period October 2003 through September 2004. Average available N applications ranged from 118 to 202 kg ha-1 of which 40% was derived from fertilizer, 30% from manure and 30% from previous legume. On a regional basis, the following percentages of corn (Zea mays) area fell within available N application categories of 0, 1-80, 81-160, 161-240 and >240 kg ha-1, respectively: in the northeast (NE) region, <1, 26, 33, 21 and 19% of the total corn area (504 ha); in the south-central (SC) region, <1, 39, 41, 14 and 5% of the corn area (576 ha); and in the south-west (SW) region, 0, 31, 45, 14 and 10% of the corn area (180 ha). Average available P applications were similar (16 to 18 kg ha-1) across regions, of which 70% came from manure and 30% from fertilizer. On a regional basis, the following percentages of surveyed cropland area fell within available P application categories of 0, 1-24, 25-48, 49-72 and >72 kg ha-1, respectively: in the NE, 30, 50, 15, 4 and 1% of the cropland area (1340 ha); in the SC, 23, 54, 17, 5 and 1% of the cropland area (1168 ha); and in the SW, 41, 48, 8, 1 and 2% of the cropland area (542 ha). Of the total cropland area (ha) across all regions that received manure during winter, 7-25% were within regulated surface water buffer zones. In the NE, SC, and SW regions respectively, 100, 83 and 63% of winter-spread cropland area received available P application rates < 24 kg ha-1, the 1-y crop P replacement ceiling set by State regulations. Overall study results indicated that farmers were integrating fertilizer-manure-legume management much more than previously thought, that relatively few farms would have to change current practices to adhere to the proposed Wisconsin Code 590 Nutrient Management Standard, and that a relatively small proportion of farmers were employing nutrient management practices that may be detrimental to water quality.

Last Modified: 10/25/2014
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