The objective of this study was to compare till and zero till systems in terms of their impact on water infiltration, soil moisture content, root diseases and nematode populations. Using a 12 year trial with 16 different treatments, results indicated that no till systems with residue retention were the highest yielding, but there was increased disease and nematode populations in the zero till systems. However, no till systems with residue retention had a lower incidence of disease and pests than no till without residue retention. The researchers point out that while increased root disease may have impacted crop performance, the additional gains to water infiltration and soil moisture content more than offset this to increase yields.