Doctor of Philosophy (PhD)


Agricultural Economics

Document Type



Conventional drainage systems and poorly drained soils tend to increase row crop agriculture nutrient and sediment effluent loads. Best management practices help reduce row crop production environmental pollution. This dissertation looked at nutrient and tillage management practices that could help farmers address future total maximum daily loads (TMDLs) for the Cabin-Teele sub-watershed, within the lower Mississippi River Basin. The dissertation had two objectives. The first objective was to examine the economic and environmental impact of tillage and nutrient management practices in reducing agricultural pollutants to meet TMDL requirements. Relative cost effectiveness of different tillage and nutrient management practices were analyzed as part of this objective. The second objective was to evaluate and compare social net economic benefits of achieving specific sediment and nutrient criteria reductions; nitrogen, phosphorus and sediment reductions individually, and concurrently (reducing all three simultaneously) given a set of agronomic practices in the watershed. Results showed reduced tillage system were preferred to either conventional tillage or conservation tillage in Cabin-Teele because of their higher net revenue per acre. Additionally, the intermittent occurrence of hardpan soils (due to heavy rainfalls) in this watershed required disking every four to five years to help maintain yields. Simulated results showed that nitrogen fertilizer management, and conservation tillage, were cost-effective in helping reduce nutrient effluent runoff. Changes in tillage management helped producers reduce sediment loading in the watershed. In the scenario with nutrients and sediment reduced simultaneously, the most binding cropland pollutant was phosphorus.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

John Westra