Comparison of selected reduced-tillage planting systems in cotton and soybeans

Performances of five commercially available no-tillage and reduced-tillage planting systems were evaluated for cotton and soybean production at the Milan Experiment Station in Gibson County, Tennessee. Evaluations were based upon consistency of seed placement, ability to produce a viable stand, soil moisture preservation, and crop yield.

Seed placement data were collected from randomly selected row segments seeded with each planter. Seeds were excavated and coefficients of variation were determined for both seed depth and spacing.

Stand counts, canopy measurements and relative root length determinations were taken during several stages of plant growth. Stand and canopy dimensions varied at times due to planting system, and in some cases root growth also differed by row spacing and sampling depth. Soil cores were extracted on 18 August 1987 for soil moisture and plant root length determination. These cores were taken both directly in the drill and in the row middles to a depth of 90 centimeters in 15-centimeter depth increments. Tillage treatment, and on several occasions row spacing, were found to significantly effect both soil moisture and relative root length. A combine was used to harvest soybeans. Cotton plots were stripper harvested since row spacing was less than that required for conventional picker harvesting. Planting system had no significant effect on yields of either soybean or cotton.