A partial budget analysis for phosphorus-based nutrient management plans for Connecticut dairy farms
This study estimated changes in costs of manure handling, costs of the fertilizer replacement value of manure, and expected changes in net revenues associated with the implementation of manure nutrient management plans (NMPs) based on the agronomic critical concentration for P using a partial budget analysis. The net revenue from manure management practices traditionally used by farmers in a baseline year was compared with the expected net revenue from practices recommended in NMPs for four dairy farms over 4 or 5 yr in Connecticut. Yields were not measured across the 2862 field-years. Compared with the baseline year, the average annual estimated change in net revenue associated with manure applications based on the NMPs was a negative $2,900 for one large farm and a positive $17,600 for the other large farm, while the net revenue change was a positive $200 and $1,400 for the two medium-sized farms. In years after the baseline the average annual estimated change in net revenue for manure management practices for the NMPs compared with the practices reported by farmers was a negative $2,200 for one large farm and a positive $19,300 for the other large farm; the net revenue change was a positive $2,500 and $1,300 for the medium-sized farms. The net revenue changes from the NMPs were determined largely by the existing soil test P and K values. The complexity of implementing the NMPs made it difficult to obtain the expected net revenue changes.