Continuous Application of No-Tillage to Ohio Soils: Changes in Crop Yields and Organic Matter-Related Soil Properties
This chapter describes some of the changes observed in soil properties that are affected by long-term maintenance of no-tillage (NT). The most visible effect of applying continuous NT cropping practices is the rapid development of a residue cover on the soil surface. The residues deposited on the soil surface during the first year of NT seem to have little permanent impact on organic matter-related soil properties. Higher rates of fertilizer nitrogen (N) generally are required to achieve the same level of yield for NT as compared to plow tillage. This is attributed to greater immobilization of N fertilizer by soil microorganisms in the surface soil layer during the decomposition of freshly deposited plant residues. Comparison of loss of soluble organic carbon from NT and plowed soils, however, is frought with difficulty because of the many hydrologic and chemical variables associated with its transport.