Table 1. Effect of no-till on the soil environment. Soil physical characteristics –Increased soil water –Moderation of soil temperature –Increased bulk density Soil chemical characteristics –Increased soil organic matter –Decreased ph at the surface

Table 2. N immobilization of 15 N fertilizer (%) (Rice & Smith, 1984)

Table 3. N Mineralized From Sod (Rice et al., 1987).

Table 4. Effect of tillage systems and N fertilization on N mineralization (Espinoza, Y ) TillageNitrogen Potential N min Actual N min No tillageNo nitrogen277c40b Manure490a98a Fertilizer320c70ab Conventional tillageNo nitrogen297c53b Manure431b87a Fertilizer348bc72ab

Figure 1. Effect of tillage on soil organic carbon after 10 y (0-5 cm). a bb bc c c

Figure 2. Effect of tillage and rotation on soil organic carbon after 34 y (0-30 cm) (Dick and Durkalski, 1997). a b b bc c c

Figure 3. Effect of tillage on soil nitrogen after 10 y (0-5 cm) a b b bc cdd

Figure 4. Effect of long-term tillage on N mineralization (Rice et al., 1986)

Figure 5. Effect of tillage and N source on denitrifying enzyme activity (0-5 cm) (Kocyigit, 1998).