Economics of conservation tillage in a wheat-fallow rotation

Wind erosion and blowing dust on conventionally tilled winter wheat (Triticum aestivurn L.)-summer fallow cropland in eastern Washington, USA, reduces soil productivity and can contribute to poor air quality. Conservation tillage during fallow has long been known to curtail erosion and dust, but conventional tillage (CT) is still practiced on more than 80% of the cropland in the region. This paper reports the economic results of a 5-yr (1995-1999 harvest years) tillage system study at Lind, WA. The site averages 244 mm of annual precipitation, and the soil is a Shano silt loam (coarse-silty, mixed, superactive, mesic Xeric Haplocambids). Tillage systems were (i) CT, (ii) minimum tillage (MT; herbicides and tillage), and (iii) delayed MT (DMT; herbicides and delayed tillage). Wheat grain yield across years ranged from 1.79 to 5.20 Mg ha(-1), but there were no differences in grain yield among tillage systems in any year or when analyzed across years. Tillage systems were economically equivalent based on market returns over total production costs, but DMT was slightly less profitable than CT based on market returns over variable costs. Economic analysis indicates that no subsidies should be required to entice producers to switch from CT to NIT fallow because the systems are equally profitable. Because there is no short- or long-term economic sacrifice for converting to the soil-saving MT system, it represents a win-win solution for farmers and the environment.