Cotton Growth and Yield Response to Short-Term Tillage Systems and Planting Date in North Carolina

Tillage practices, cover crops, and planting dates can influence soil moisture and temperature conditions at planting and cotton (Gossypium hirsutum L.) stand establishment and yield. A study was conducted in North Carolina at two locations from 2014 through 2016. Treatments included six tillage systems of fall and spring conventional raised beds and flat strip tillage planted in early and late May, with and without a wheat (Triticum aestivum L.) cover crop. Tillage treatments include conventional spring raised beds, fall strip till, stale seedbed, at-plant strip till, pre-plant strip till, and stale seedbed with at-plant strip till. Except for fall strip tillage, no tillage systems reduced plant populations compared to conventionally tilled cotton in any environment. Crop growth rates were similar in conventional and spring strip-till systems and were lower in four planting date environments with stale seedbeds. In 2016, in-row soil resistance was measured from 0- to 30-cm depth using a conical penetrometer both at planting and post-harvest. Plots without any spring tillage had the greatest soil resistance for all measurements and depths. All plots with spring tillage had similar soil resistance to at least the 15-cm depth from which point the conventional spring beds had the least soil resistance through the 30-cm profile. Late planted cotton in 2014 showed inconsistent yield differences among tillage systems between locations. When pooled over location and year for 2015 and 2016, however, tillage system did not influence cotton yield. These data indicate that cotton yields in reduced-till systems are comparable to cotton grown in conventional systems in North Carolina soils.