A snapshot of dairy nutrient management
By Marg Land
In August, the U.S. Department of Agriculture’s National Animal Health Monitoring System [NAHMS] released its most recent report, Nutrient Management Practices on U.S. Dairy Operations, 2014.
The study provides a snapshot of manure management and storage practices on dairy operations across the country. While the data is four years out of date – such is the nature of census information – it does make for interesting reading.
The core data comes from 1,261 operations in 17 states – California, Washington, Idaho, Minnesota, Iowa, Missouri, Wisconsin, Michigan, Indiana, Ohio, Kentucky, Texas, Virginia, Pennsylvania, New York, Vermont, and Colorado. These states are home to 80.5 percent of U.S. dairy operations and 81.3 percent of the U.S. population of dairy cows. The farms were divided based on size – very small [<30 cows], small [30-99 cows], medium [100-499 cows], large [500+ cows] – and whether they were located in the East or West half of the U.S.
The following is just a small portion of the information shared in the report.
As could be expected, manure handling and storage methods varied based on the size and location of the operation. More than 50 percent of very small, small and medium farms [combined] kept cows out on pasture while more than 50 percent of medium and large operations [combined] scraped manure from an open/dry lot.
More operations in the West than the East scraped an open/dry lot or used an alley flush as their primary means of handling manure. No operations in the West used a gutter cleaning system or slotted flooring.
Solid manure was stored and/or treated on 92.8 percent of operations. A higher percentage of small operations [95.3 percent] stored and/or treated solid manure compared with large operations [87.8 percent]. The use of a manure spreader decreased as herd size increased. Manure packs were used by a higher percentage of small [25 percent] and medium operations [30.9 percent] compared with large operations [14.1 percent]. A higher percentage of operations in the East used a manure spreader or manure pack to handle the majority of solid manure. In general, the percentages of operations that used outside storage for solid manure increased as herd size increased.
Liquid manure was stored or treated on 59.3 percent of operations. The percentage of operations that stored or treated liquid manure increased with herd size. A lower percentage of small operations [15.4 percent] stored liquid manure in an untreated earthen basin compared with medium [34.1 percent] and large operations [40.1 percent].
The average number of days an operation could store manure increased as herd size increased. On average, all operations could store manure for 161.2 days. Operations in the West could store manure for more days [399.3 days] than operations in the East [138.3 days]. Less than 15 percent of operations of any herd size or from any region could store manure for 365 days or more.
More than 90 percent of all operations applied solid or liquid manure to land either owned or rented. Surprisingly, there was a small contingent [11.9 percent] that gave manure away.
To view the report in its entirety, visit aphis.usda.gov/nahms