Evaluating long-term economic and ecological consequences of continuous and multi-paddock grazing - a modeling approach

Aside from overstocking, inappropriate grazing management strategies may cause rangeland degradation in commercial scale ranches. In this paper we construct a dynamic model to study the economic and ecological consequences of continuous and multi-paddock (MP) grazing. Simulations on long-term economic profitability and ecological indices were carried out for continuous vs. MP grazing management strategies under different grass growth rates, grass dormant periods, initial ecological conditions and various installation costs for MP grazing. Results show that compared to continuous grazing, MP grazing on large commercial ranches greatly increases the optimal 30-year net present value (NPV) by sustaining much higher stocking rates. At realistic stocking rates, MP grazing both increases long-term economic profit and improves ecological conditions. The advantage of MP grazing is more pronounced under xeric conditions, longer grass dormancy period, and initial prevalence of less palatable grasses and weeds. However, ranch managers for smaller ranches and/or ranches under short-term leases are less likely to adopt MP grazing due to its diminished economic advantages on those ranches.