Cornell University’s Nutrient Management Spear Program (NMSP) is helping farmers evaluate their nutrient use through the Cornell whole-farm nutrient mass balance (NMB) tool. This project, led by NMSP Research Associate Olivia Godber, is focused on guiding farmers toward their “Optimal Operational Zone” or “Green Box,” the sweet spot where milk production efficiency is high and environmental impact is low. Read on to learn how this program supports farmers and to find out how to join.
When the NMSP team calculates a whole-farm NMB, they evaluate nutrient use on farms using a software tool that targets three critical macronutrients: nitrogen (N), phosphorus (P) and potassium (K). These macronutrients, referred to holistically as NPK, are important because they are needed in large amounts to produce healthy, high-yielding crops to feed cows.
“More than 20% of New York’s milk is now assessed for nutrient footprint,” said Quirine Ketterings, professor of nutrient management in agricultural ecosystems in the Department of Animal Science and lead for NMSP. “This emphasizes the importance that farmers place on evaluating their nutrient use and looking for opportunities to improve the sustainability of their farms.”
"Almost all farmers continue to participate after the first year as they see the value in this assessment. Many of them also report being more prepared for making management changes in future years, and appreciate the need for better record keeping because that has advantages beyond the NMB assessment.”
Dairy farmers import and export products to and from their farms to support their day-to-day operations, produce food and make a living. “Nutrient imports” purchased by the farmer may include feed concentrates, forage, fertilizers, purchased animals and bedding. “Nutrient exports” include milk, animals sold or moved from the farm, crops sold and any manure that might leave the farm.
The NMB is calculated by taking the difference between a farm’s NPK nutrient imports and exports within one calendar year.