An integrated North Florida dairy farm model to reduce environmental impacts under seasonal climate variability

Dairies are challenged to comply with stricter environmental regulations and remain economically viable. This paper studies the potential use of ENSO-based climate forecasts to reduce N leaching without reducing profits on North Florida dairies. A model was created to perform the analyses, the Dynamic North Florida Dairy Farm Model (DyNoFlo). DyNoFlo is an integrated dynamic model that incorporates Markov-chain simulation of cow flows and crop model simulations for historical climatic years (El Ni (n) over tildeo, La Ni (n) over tildea, and Neutral years). It also includes optimization of managerial options. It responds to dairy-specific environment (climate and soils) and management (livestock management, waste management, crop systems management). The DyNoFlo model was designed to be a tool for producers, regulatory agencies, and extension services in addition to a research tool. Analyzing a typical North Florida dairy farm, it was found that N leaching was highest during winter El Ni (n) over tildeo years. Sandy soils were substantially more prone to leach N, and perennial grasses were better to prevent N leaching. The typical farm could decrease N leaching up to 23% in an El Ni (n) over tildeo year and still maintain profit by adjusting protein in the diet, confinement time for milking cows, and combining perennial grasses and forages in pastures and sprayfields. Application of the DyNoFlo model to small, medium, and large dairy farms showed that they could decrease their N leaching by 9, 20, and 25%, respectively, without reducing profits by varying management strategies according to ENSO phases. (c) 2005 Elsevier B.V. All rights reserved.