Effect of ecological and conventional managements on soil enzymatic activities in coffee agroecosystems

Abstract

Understanding the impacts of agricultural practices on soil quality indicators, such as enzymatic activities, is of great importance, in order to advance in their diagnosis and sustainable management. This study aimed to evaluate the effect of ecological and conventional agricultural managements on enzymatic activities of a soil under coffee agroecosystems. The enzymatic activities were associated with the biogeochemical cycles of nitrogen (urease and protease), phosphorus (acid and alkaline phosphatase) and carbon (β-glucosidase), during the rainy and dry seasons. Physical-chemical soil proprieties were also assessed and related to resilience scores linked to the climatic variability reported for the areas under study. The activities of urease, alkaline and acid phosphatase and ß-glucosidase were statistically higher in ecological agroecosystems than in conventional ones. This may be attributed to the greater application of organic waste in the ecological environment, as well as to the absence of pesticides and synthetic fertilizers, which allow better conditions for the microbial activity. The resilience scores to the climate variability that showed the highest correlations with the assessed enzymatic activities were: the farmers' knowledge on soil microorganisms, non-use of pesticides and synthetic fertilizers and non-dependence on external supplies. It was concluded that the enzymatic activities are modified by the management systems, being specifically favored by the ecological management. This agroecosystem, in the long term, ensures an efficient use of the soil resources, with a lower degradation and contamination.

Cambios en calidad del suelo asociados a la aplicación de técnicas de agricultura ecológica en plantas café bajo diferentes coberturas

“…As for the nitrogen cycle, the urease activity was determined, which is based on the colorimetric determination at 690 nm of the released ammonia after incubation with a solution of urea for 2 h, at 37 ºC (Avellaneda-Torres et al, 2018). Finally, the study determined the protease activity by incubating the soil samples for 2 h at 50 ºC using casein as substrate (Caballero-Vanegas et al, 2018) after incubation for 2 h at 50 ºC and a pH 8.1. In this method, the released amino acids reacted with the Folin-Ciocalteu reagent in an alkaline solution to form a blue complex that was colorimetrically evaluated (700 nm) (Avellaneda-Torres et al, 2018).…”