Soil microbiological indicators in Coffea arabica crops under different weed management strategies

Abstract

Microbiological variables can be sensitive indicators of changes in the physicochemical properties of soils resulting from disturbances caused by practices of weed management. The objective of this work was to evaluate the impact of weed management strategies on the soil, using microbiological indicators over four-year time measures (two in the dry and two during the rainy weather season). The experiment was carried out in a coffee plantation field (Coffea arabica), in a randomized block design with five treatments. The treatments corresponded to the cultivation of Urochloa ruziziensis and Pueraria phaseoloides managed by mowing, maintenance of spontaneous vegetation and control by mowing, control of spontaneous vegetation by application of herbicides (glyphosate or glyphosate + 2,4-D), and manual weeding using a hoe to maintain the soil without vegetation cover. Soil C – CO2 evolution, basal respiration (RR), biomass carbon (Cbio), and metabolic quotient (qCO2) were evaluated. Treatments with U. ruziziensis and P. phaseoloides presented lower qCO2 values, indicating more stable systems and closer to equilibrium. Cbio was higher in the treatment with P. phaseoloides, indicating better soil fertility and carbon input conditions. The microbiological indicators allowed us to conclude that management methods that form a cover over the soil favor the maintenance of soil quality and the sustainability of the system.