Monday, November 2, 2009
Convention Center, Exhibit Hall BC, Second Floor
Four years of mass nutrient balance (MNB) assessments of dairy farms in
New York showed the MNB to be an effective tool in raising awareness of farm-scale nutrient use efficiency and loss, and as an end-of-year management evaluation tool. However, a MNB report does not give sufficient guidance on specific management changes to consider for the following year. The objective of our research was to identify a set of farm performance indicators that helps producers and their advisors select management alternatives. Two case-study farms were assessed on an annual basis for five years. The performance indicators reported in the literature were evaluated for their: 1) correlation with the annual farm-scale MNB, 2) ease of interpretation by dairy farmers and farm advisors, and 3) ease and repeatability of data collection. The case studies showed farm density per tillable unit of cropland and animal density adjusted for manure export to be effective whole-farm level tools. The most effective herd indicators included percent of heifers in the herd, mature cow cull rate, percent forage in the ration, and feed nutrient use efficiency. Crop indicators with the greatest potential included percent of yield potential achieved, manure and fertilizer N and P2O5 use efficiency, distribution of soil test P and K, fertilizer P and K use per unit of P or K deficient cropland, and cool season grass P and K levels. The main limitations to calculating these indicators included lack of on-farm record-keeping and integrated software tools.