Microbial activity in soil with onion grown in a no-tillage system with single or intercropped cover crops

Abstract

Microbial biomass is a driving force in the dynamics of soil organic matter, and microbial activity is an indicator of soil quality in agroecosystems, reflecting changes in management practices and environmental conditions. We evaluated the effect of monoculture and intercropped winter cover crops on soil chemical attributes, microbial biomass carbon (MBC), basal respiration (BR), metabolic quotient (qCO2), urease, β-glucosidase, and fluorescein diacetate (FDA) hydrolysis activity, as well as onion yield in a no-tillage system. Soil is a Typic Humudept, and treatments were control with spontaneous vegetation, barley, rye, oilseed radish (OR), OR + rye, and OR + barley. The soil was sampled (0-10 cm) five times between June and December. There were no differences among treatments for MBC and BR, and the highest values for those attributes occurred in June, when cover plants were in their initial stage. Although, qCO2 was not affected by any treatment, it varied among sampling periods, ranging from 0.62 to 10 µg C-CO2 mg-1 MBC h-1, indicating a low- or no stress environment. Cover crops had little influence on enzyme activity, but FDA was lowered in areas with single crops of barley and rye. Average onion yield in cover crops treatments was 13.01 (Mg ha-1), 30-40% higher than in the control treatment.

Soil microbial biomass carbon and Jatropha curcas yield intecropping with forages and crop species

“…Among the sampling times, the evaluation conducted in May, 2012 indicated higher values of metabolic quotient (qCO2) in relation to February, 2012. The highest values in this ratio were observed in May, according to Souza et al (2020), due to the rise in microbial biomass carbon and basal respiration, which were influenced by the presence of the cover crops.…”

“…Lowest values were observed in the soil under J. curcas intercropping with P. maximum cv. massai, C. cajan and C. spectabilis, according Souza et al (2020), possibly reflect higher efficiency of the microbial biomass in the use of organic C, meaning that less C is lost as CO2 through respiration and more C is incorporated into microbial cells. However, this outcome may not directly reflect an increase in agricultural productivity (Souza et al, 2020).…”

Applications and Market of Micro-Organism-Based and Plant-Based Inputs in Brazilian Agriculture

“…Furthermore, it is important to emphasize that both crop rotation and intercropping play a pivotal role in promoting the diversity of plant species in the agricultural environment. This results in the enrichment of soil microbial activity, which contributes to the reduction in pest pressure while simultaneously enhancing soil quality [77].…”