Fall Planted Legume-Cereal Mix Impacted Soil Properties but Fall Short of Weed Suppression in Tilled and No-tilled Chickpea Production Systems

Authors: MERSHA, ZELALEM - Virginia State University; IBARRA-BAUTISTA, MICHAEL - Virginia State University; Birru, Girma; BUCCIARELLI, JULIA - Virginia State University; GITHINJI, LEONARD - Virginia State University; SHIFERAW, ANDUALEM - University Of Nebraska; REN, SHUXIN - Virginia State University; RUTTO, LABAN - Virginia State University

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/31/2025
Publication Date: 8/6/2025
Citation: Mersha, Z., Ibarra-Bautista, M., Birru, G.A., Ren, S., Rutto, L., Githinji, L. 2025. Fall Planted Legume-Cereal Mix Impacted Soil Properties but Fall Short of Weed Suppression in Tilled and No-tilled Chickpea Production Systems. Agronomy Journal. 15(8):1893. https://doi.org/10.3390/agronomy15081893.
DOI: https://doi.org/10.3390/agronomy15081893

Interpretive Summary: Fall planted cover crops (CCs) have long been recognized as a sustainable agricultural practice serving multiple purposes including enhancing biodiversity, improving soil health, reducing erosion as well as suppressing pests, diseases and weeds. Despite the numerous benefits, the implementation of CCs poses challenges, including the selection of appropriate species, timing of planting and termination, and potential competition with main crops for resources. The effect of fall planted CCs on soil properties was examined as the efficiency of five cover crop terminations methods namely a) green manure (GM), b) GM plus pre-emergence herbicide (GMH), c) burn (BOH), d) crimp (CR) and e) mow-mulch (MW) were evaluated in suppression of weeds in chickpea fields. This study underscores the multifaceted agronomic benefits of the winter rye and hairy-vetch cover crop system in the short-term and its added potentials in the long-term including soil health and weed suppression. Integrating cover crops into broader cropping systems will require continuous monitoring and adaptive management strategies to balance ecological and agronomic goals. Future studies shall prioritize strategies that ensure early planting and rapid canopy establishment of selected CCs that suit the climatic conditions in chickpea production system.

Technical Abstract: Cover crops (CCs) are known to offer several benefits including soil health improvement, nutrient management, erosion control and suppression of diseases and weeds. In this study, the effect of fall planted winter rye WR alone (2021) or mixed with hairy-vetch HV (2022 and 2023) was studied at Randolph farm in Petersburg, Virginia. The objectives of the study were two fold: (a) to examine the effect of fall planted CCs on soil properties following a monthly growth dynamics and a harvest from fifteen 0.25 m2-quadrants and (b) evaluate efficiency of five cover crop terminations namely a) green manure (GM), b) GM plus pre-emergence herbicide (GMH), c) burn (BOH), d) crimp (CR) and e) mow-mulch (MW) in suppression of weeds in chickpea fields. Weed distribution particularly nutsedge was spotty with heavy dominance in eastern side of the field. Growth dynamics varied between planting time of CCs and it was explained well by an exponential growth in fall 2022 (R2 = 0.994, P < 0.0002) but with three-parameter sigmoidal curve (R2 = 0.972, P < 0.0047) in fall 2023 planting. The total biomass added to the soil was averaged 55.8 and 96.9 t/ha for the fall 2022 and 2023 plantings, respectively. Weed suppression was consistently better on plots with GMH than GM alone though the latter was not significantly different with the no-till systems at the end of the season. Kabuli type chickpeas under GMH have significantly higher yield than the two desi types. Polled data over the three years was best fitted to three parametric logistic growth curves with predictions of half-time to 50% weed coverage estimated at 35 (MM), 38 (CRM), 40 (BOH), 46 (GM) and 53 (GMH) days after planting. Relapses of CCs were a consistent issue in the no-till systems but significantly in BOH and MW than CR. Whereas added organic matter was clearly discernible, cover crop planting alone does not significantly contribute to weed suppression.