Research is needed that simultaneously evaluates production and conservation outcomes of precision agriculture practices.  From over a decade (1993-2003) of yield and soil mapping and water quality assessment, a multi-faceted, “precision agriculture system” (PAS) was developed and initiated in 2004 on a 36-ha field in Central Missouri. The PAS assessment was accomplished by comparing it to the previous decade of conventional corn-soybean mulch-tillage management. The employed PAS plan takes advantage of targeted management that addresses crop production and environmental issues. For example, wheat was grown in instead of corn for field areas where depth to the argillic horizon was shallow and not profitable under corn production. These same areas were more vulnerable to runoff generation and herbicide and nutrient losses. This portion of the field soil degradation has been the greatest and with PAS was planted in a wheat-soybean rotation, with a cover crop before soybean. Cover crops were also used in the other portions of the field cropped in a corn-soybean rotation.  No-tillage was employed over the whole field. Additional site-specific inputs have include variable-rate N for wheat and corn using canopy reflectance sensing, variable-rate P, K, and lime using intensively grid sample data, and targeting of herbicides based on weed pressure. Result findings to be presented showing the effects of PAS will include a spatial assessment of soil nutrient change, production and production risk, change in soil quality indicators, and surface and ground water quality. For example, surface runoff during the January to June time period has been found to be significantly less (~30%) when compared to the management prior to PAS. We conclude this effect to largely be the result of including cover crops into the management, including the use of winter wheat on the north end of the field. Sediment loss with PAS has been reduced 80% compared to pre-PAS years. This sediment reduction occurred during a period when sediment from the larger watershed (1,100 km²) containing the evaluation field doubled in sediment loss. Ground water nitrate-N in the shallow (< 20 m depth) aquifer has remained unchanged in most of the 25 monitoring wells.  In a few wells, marked increases in nitrate-N have occurred and presumed to be the result of preferential pathway development after extreme droughty years whereby the surface soil was connected to the ground water. Yield risk as measured by location yield coefficient of variation has decreased where wheat replaced corn, but has remained unchanged for soybeans.