The nutrient management manager at TeamAg in Lancaster County, PA describes his experience with separated digestate on ten American farms with anaerobic digesters.

There are plenty of opinions about the properties of the digested, then separated, solids and liquids that are produced by a methane digester. Lots of conclusions, theories…and uncertainty.

In the United States, a country of only two hundred sixty agricultural biogas systems, the longtime nutrient manager at ten of those farms has some valuable observations. Jedd Moncavage’s base is Lancaster County, PA, the home of one of America’s very few digester clusters. A total biogas support industry has evolved in Lancaster including generator service, parts and plant operators. Just as important is the “knowledge sharing” that benefits all the region’s farms.

 

While hosting a visiting Chinese agricultural group, Jim Muir asked Jedd questions of interest to potential digester owners in the United States as well. His responses result from an education in soil science at Penn State, work at NCRS and most importantly real-life experience, He has handled the nutrient management at multiple farms with digesters for TeamAg over an eighteen year period.

Below are some answers regarding the positive aspects of digested and separated manure based this experience. They include the effect on Mastitis rates, increased plant availability of nitrogen and the movement of phosphorus from the liquid to the solid digestate portion.

Digested bedding solids and Mastitis reduction. (:37)

Increased “plant available” nitrogen, reduced phosphorus in liquid digestate and increased phosphorus in solid portion. (1:02)

Benefits of spreading liquid digestate including land absorption (:47)

Liquid digestate facilitates “no till” farming and weed seed reduction (2:17)

Manure management conference organized by Muir for southern New England dairy farmers, the Dept. of Energy, Environmental Protection (DEEP) and others. Jedd Moncavage described the benefits of digester output on cropland in Pennsylvania. Three of the farms purchased biogas systems and a fourth recently signed a letter of intent.

 

Jim Muir with Massachusetts farmer (left) and Jedd Moncavage (right) at nutrient management conference for potential digester owners he organized in southern New England.