New York updates manure crediting based on research

By Blake Jackson

New York is revamping its manure crediting system to account for modern farming practices. The farmer-led Northern New York Agricultural Development Program (NNYADP) is conducting a multi-year study on the value of manure as fertilizer. This research will inform updates to the crediting system, ensuring accurate reflection of manure's nutrient content and benefits to crops.

"We're evaluating the nutrient value of various manure sources, including new types not considered in the original system," explains Dr. Quirine Ketterings, who leads the project. "We're also examining how manure impacts crop yields and quality beyond what inorganic fertilizers alone can achieve."

The project focuses on two key aspects: nutrient variability and manure's impact on crops.

Nutrient Variability:

• Manure composition can differ significantly between farms, storage methods, and even within application periods.
• The study, involving 16 manure sources from five farms, revealed that farm-specific management practices heavily influence nutrient content.

Manure's Impact on Crops:

• Field trials in 2023 showed that spring-applied manure improved silage yield and quality at both test locations.
• The research compared plots with and without manure application, and then subdivided each plot for varying nitrogen sidedress rates.
• Results showed that manure application significantly reduced the amount of additional nitrogen fertilizer needed for optimal yields. Farm A, for example, required no sidedress nitrogen when manure was applied, compared to 109 lbs/acre without manure.
• Manure application also led to economic benefits. At Farm A, the economic yield with manure was $1,137/acre compared to $986/acre without manure (application costs not included).
• Manure's influence extended beyond nitrogen. Farm A's manured plots showed increased levels of potassium, calcium, magnesium, and copper in the silage.

The positive results from 2023 have secured further funding for the NNYADP Value of Manure project in 2024. The ongoing research will contribute to a more accurate manure crediting system, benefiting both farmers and the environment.

For detailed project information, visit nnyagdev.org or the Cornell Field Crops blog "What's Cropping Up?". The project is funded by the New York State Legislature and administered by the New York State Department of Agriculture and Markets.

Photo Credit: istock-chas53