Cover crop and tillage effects on soil microbial communities in a corn cropping system

Abstract Soil microbial communities have numerous soil ecological and physiological functions. However, knowledge is lacking on the interaction effects of no‐till and cover crops (CC) practices on these soil health indicators. This study evaluated the effects of CC and tillage on soil microbial communities in a corn ( Zea mays L.) system. The study was conducted for 2 consecutive years on plots allotted to three practices: (1) no‐till and cover crop (NC), (2) conventional till and no cover crop (CN), and (3) no‐till no cover crop (NN). A grass strip (G) was used as a reference, assuming it was subjected to the least disturbance. Surface (0–5 cm and 5–10 cm) soils were sampled over 2 years in April and October. Soil microbial biomass was measured using phospholipid fatty acid (PLFA) analysis. Seasonal variations indicated greater microbial biomass in fall than in spring. The G and NC significantly increased soil microbial biomass at both depths compared to CN and NN during fall 2021 sampling and numerically in fall 2020, where greater changes were observed at 0‐ to 5‐cm depth. In fall 2021 sampling, NC practices had 65%–75% more total microbial biomass than CN and NN at both depths ( p < 0.001), with total bacterial biomass 70% greater ( p < 0.002) and total fungal biomass 75%–85% greater ( p < 0.007). NC also showed 85% more actinomycetes biomass than CN at 5‐ to 10‐cm depth ( p < 0.05). The study concluded that soil microbial communities significantly improved after two CC seasons, with higher microbial biomass in fall compared to spring.