Impacts of Agricultural Policies on Compost Demand, Farm Size, and Environmental Consequences in US Dairy Farming

Abstract The consolidation of US dairy farming has led to concentrated manure production, resulting in manure management challenges and GHG emissions from unmanaged manure. Policies such as subsidizing compost production and implementing strict Nutrient Application Standards incentivize composting of manure and mitigate GHG emissions while impacting compost demand and herd size. Our model indicates that both policies would increase compost manure production and decrease compost price which would reduce unsold fresh manure, and cut emissions. However, when considering the size of the farm, subsidizing compost production and strict Nutrient Application Standards have different impacts. Nutrient Application Standards increase the cost of managing excess manure, leading to smaller herd size whereas, the subsidy has no impact on herd size as long as the farm retains unsold manure.