Soil moisture and cotton emergence response to cover crop residue management methods

Authors: Kichler, Corey; Watts, Dexter; Torbert Iii, Henry; Kornecki, Ted; PRASAD, RISHI - Auburn University

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/2023
Publication Date: 10/30/2023
Citation: Kichler, C.M., Watts, D.B., Torbert III, H.A., Kornecki, T.S., Prasad, R. 2023. Soil moisture and cotton emergence response to cover crop residue management methods [abstract]. American Society of Agronomy. St. Louis, MO. Oct 29th-Nov 1, 2023.

Interpretive Summary:

Technical Abstract: The benefits of using cover crops are well known, but methods on how to terminate and manage surface cover residues are often questioned by producers. Mowing and rolling/crimping are two methods that keep residue on the soil surface during the growing season, which can improve soil moisture retention compared to conventionally tilled systems. However, cover crop residues can often interfere with planters, leading to slower emergence and ultimately lower yields. This experiment investigates three different termination methods for a cereal rye cover crop including mowing (MOW), roll/crimp (ROLL), and mowing with incorporation (MOWINCORP) and their effects on soil moisture retention and cotton seed emergence during the 2022 growing season. An emergence rate index (ERI) was used to determine differences between the systems as well as weekly volumetric moisture readings. Results reveal that cotton emergence was significantly different for termination method. The MOW method was significantly lower at 14.0 compared to both ROLL (ERI=15.4) and MOWINCORP (ERI=15.9). This is due to the MOW method creating finely chopped and loose residue that can obstruct seed-to-soil contact by lessening the effectiveness of the cutting discs and enabling the planter to push loose residue into the furrow, known as “hair pinning”. When residue is present with the seed inside the furrow, the seed may not be accurately placed to the correct depth or properly packed in the soil, thus negatively effecting germination. Volumetric soil moisture was significantly higher for MOW and ROLL methods by 14.2-51% compared to MOWINCORP at various times during the first four weeks after cotton planting. Cotton yield, although not significant, was 6.2-6.9% less for the MOWINCORP plots compared to the MOW and roll plots. Cover crop termination methods along with surface residue condition can affect seed emergence and soil moisture.