How do SOIL CONDITIONS affect cultivation?

Some growers aggressively till and level the soil prior to planting to improve physical weed control. Other things equal, it is clear that this is a good strategy as it helps to ensure uniform and rapid emergence of the crop and more consistent depth of cultivation tools. However, tillage and bed preparation are not free, and excessive tillage can rapidly degrade soils. Moreover, some forms of bed preparation may actually reduce efficacy of cultivation.

At Michigan State University, one of our graduate students (Daniel Priddy) is exploring how soil surface characteristics including surface roughness, soil moisture and crusting influence the efficacy of various tools. Here is an Abstract which summarizes some of his results:

Soil Surface Effects on the Efficacy of Flextine Cultivation in Vegetables.
Daniel Priddy and Dan Brainard, Michigan State University

Seed bed preparation and soil management history are thought to have a large impact on the efficacy of mechanical cultivation, but limited information is available on of the mechanisms of these effects, and their implications for management. In a series of field trails, we tested how pre-plant bed preparation (rolled vs not), historic compost use (12 previous years of annual applications vs none), and application of molasses (to induce soil crusting) influenced soil surface characteristics and the efficacy of flextine cultivation in bush beans ( Phaseolus vulgaris ) and sweet corn ( Zea mays L . ). Rolling beds prior to planting generally resulted in lower soil surface roughness, greater soil micro-penetrometer resistance, higher soil moisture content, and reduced efficacy of flextine cultivation compared to unrolled beds. Historic compost and molasses applications had few impacts on these soil characteristics and little or no effect on flextine efficacy. The results of this study challenge conventional cultivation wisdom that rolling seed beds improves cultivation efficacy by facilitating more uniform tine working depth. This potential benefit may be offset by higher soil moisture and surface hardness, which reduce the capacity of tines to disturb soil and increase the re-rooting potential of disturbed weeds.