Individual and community decision-making for livestock farmers affected by locusts
Locusts are a devastating problem in many regions of the world with the risk potential highest for farmers and ranchers. However, ecologists have determined a relationship between nitrogen content and locust outbreaks which could prove to be beneficial for agricultural producers. This analysis builds on this concept by determining the economic feasibility of mitigating locust outbreaks through targeted sheep and cattle grazing practices in China and Australia.
Farmers and ranchers maximize profit subject to a series of constraints. Using a constrained profit maximization model this study determines if it is optimal for the livestock producer to employ a specialized cattle grazing system, a specialized sheep grazing system, or a diversified cattle and sheep grazing system subject to a nitrogen constraint. The nitrogen constraint considers nitrogen existing on farm grassland, produced by the animal, and a nitrogen limit to mitigate locust outbreaks. By incorporating the nitrogen constraint we created an opportunity to mitigate locust outbreaks while jointly maximizing farm profit through optimal breeding, culling, and stocking rate decisions.
Data for the constrained optimization model was collected from publically available sources in Australia and survey data collected through collaborations in Inner Mongolia, China. Data included the herd composition and number of animals on the farm or ranch, breed of animals, livestock input costs, quantity of livestock sold, and received selling prices.
Results from the model demonstrate that the stocking rate is highly dependent on the nitrogen content of the farm grassland and the livestock prices received. These results are specific to one farm or ranch, however locust outbreaks are geographically distributed and do not stop at a property line. To capture this interaction we used agent based modeling to study two policy alternatives to mitigate locust outbreaks in conjunction with profit maximization. The first alternative imposes a tax on agricultural producers in the form of imposed stocking rate limits. The second result established locust protected areas as an alternative land use option. Preliminary agent based models demonstrate that the policy alternatives are regional and livestock specific.