Development and application of the Atlantic Dairy Sustainability Model (ADSM) to evaluate effects of pasture utilization, crop input levels, and milk yields on sustainability of dairying in Maritime Canada.

摘要

The objectives of this project were to evaluate the effects of confinement (0 grazing) vs. pasture based (160 days grazing) dairying, 4 milk yield goals (5500 to 11,000 kg cow-1 yr-1), and high vs. low input cropping on 7 measures of sustainability on a standardized Atlantic Canadian dairy farm. These objectives were addressed through the development and application of the ADSM, a dynamic, deterministic model constructed as a system of differential equations describing flows of C and N within a dairy farm and to/from the surrounding environment. The ADSM also models fossil energy use and economic factors. The ADSM is based on empirical data and mechanistic principles obtained from a farm survey, local data, and literature sources. It is parameterized to reflect typical Maritime conditions, and is sensitive to a number of management parameters. The ADSM models a sole dairy enterprise, including replacement stock, and a land base seeded to grass-legume forage for hay/silage, grass-legume pasture, and barley. (Abstract shortened by UMI.).