An integrated approach to nutrient management on dairy farms

We describe a novel experimental approach to assess the integrated effects of a suite of innovative measures for improving nutrient efficiency of dairy farms. The approach uses four semi-virtual farmlets, representing farm types, that combine field plots (corn and grass) with simulated cattle feeding, enabling integrated assessment of nutrient and crop measures.

Our results show overall improved crop nutrient efficiency with targeted use of separated manure fractions and strategic crop management. Cropping measures reduced leaching for both crops but manure measures increased nitrous oxide (N2O) emissions, which was mitigated with a nitrification inhibitor. Results suggest increasing land allocation for corn.