P-142 - Enhancing microbial recruitment and persistence in cover crops for control of soilborne pathogens in chile pepper

Tuesday, August 5, 2025

9:30 AM - 10:15 AM HST

Location: Exhibit Hall 3

Presenting Author(s)

SS

Soumaila Sanogo

Professor
New Mexico State University
Las Cruces, NM, USA

Author(s)

pl

phillip lujan

Assistant Professor
New Mexico State University
Las Cruces, New Mexico, United States
JF

Jason Fechner

Senior Research Assistant
New Mexico State University
Las Cruces, NM, USA
QD

Quaid Dobey

NMSU
Las Cruces, New Mexico, United States
JB

Jesus Barraza

NMSU-EPS
Las Cruces, New Mexico, United States
JC

Jonathan Consford

NMSU-EPPWS
Las Cruces, New Mexico, United States

Abstract Text: In the chile pepper industry in New Mexico, producers are exploring cover crops for establishing microbial activities in soil to reduce the impact of soilborne pathogens. A commonly adopted practice is the use of cover crop mixtures, with two or more plant species. Experiments were conducted to compare microbial biomass in one-species cover crop (triticale, variety Luoma), and a 7-species cover crop (forage pea, hybrid kale, clover, brown flax, common vetch, balansa clover, hairy vetch, winter triticale, and rapeseed). A biological mixture containing five species of Bacillus and four species of Trichoderma was applied through drip irrigation 140 days after planting. The cover crops were terminated by mowing and mechanical tillage. Soil was collected prior to planting, at 55 days after planting, and at 140 days after planting and application of the biological mixture. Total microbial biomass was measured through commercial analysis for phospholipid fatty acid (PLFA). After planting, PLFA increased 1.5-fold in cropped soil compared to uncropped soil. The increase in PLFA was comparable across the triticale cover crop and the 7-species cover crop mixture. However, after application of the biological mixture, PLFA increased 2.3-fold in the triticale cover crop and 1.6 fold in the 7-species cover crop mixture. These results suggest that cover cropping can help recruit microbial populations and increase soil total microbial biomass, an important component of soil health. Enhancing soil microbial biomass will help improve and maintain soil and crop health and crop productivity.