Lab Seminar - Economics of Livestock Farming and Nutrient Pollution

Scott Somerville presented plans for a study estimating the contribution of livestock farms to nitrate water pollution in the Central Valley of California. Nitrates are a significant health risk when present at high concentrations in drinking water. Agriculture and livestock farms can be significant sources of nitrate pollutants. This is a large concern in the Central Valley, where groundwater is used for drinking and other residential purposes. Nitrates used to fertilize agricultural fields can leach into the groundwater when applied in excessive concentrations contaminating wells used for drinking water. Livestock production contributes to this problem because manure often contains high concentrations of nitrates. Manure from livestock farms is often spread on neighboring fields as a form of fertilizer, but because it is expensive to move, farmers are incentivized to apply much more manure than is required to fertilize the crops. As a result, many of the nitrates from the manure are not taken up by the crops and can leach into the water table, contaminating wells. Despite its potential policy relevance, little work has been done in the economics literature linking the effects of livestock production practices to water pollution. Scott plans to combine livestock production data with water quality measurements from wells located around the Central Valley to identify the effects of these farming practices on residential water pollution.