The streams of North America convey excessive amounts of nitrate-nitrogen, the effects of which range from eutrophication of local surface waters to hypoxia in the Gulf of Mexico. The vast majority of the nitrate load can be attributed to agricultural sources. The diffuse nature of these sources defies the more traditional treatment strategies. The concrete and steel structures of point-source control are impractical and economically unfeasible. An alternative solution is needed. One possibility is “nitrogen farming.” Nitrogen farms could employ restored wetlands in floodplains and on bottomlands to remove the excess nitrate-nitrogen and, at the same time, provide the landowner an alternative crop. A means of buying and selling the harvest will be necessary to initiate nitrogen farming. The market could be similar to those for corn and soybeans. It would encourage landowners to enter or leave nitrogen farming depending on the price of nitrogen credits and the efficiency of their farm unit. The concept of nitrogen farming is applied to the Illinois River watershed.