Assessment of some hydrophysical properties of the soil under three vegetation covers in an organic agriculture context in the municipality of Zipacón, Colombia

Abstract

The effect of vegetation cover of coffee (Coffea arabica) plus alder (Alnus acuminata) (T1), coffee (Coffea arabica) (T2) and managed pastures (cover dominated by Digitaria decumbens) (T3) on some physical and hydrological tests of the soil of the "La Libertad" farm, in the municipality of Zipacón, established 14 years ago under exclusively organic nutritional management. The variables evaluated were depth of the A horizon, resistance to penetration, apparent density, gravimetric humidity, total porosity, organic matter and infiltration capacity. The results showed greater resistance to penetration in the coffee cover, while the greatest depth of the A horizon and the highest organic matter content and total porosity were found for the grass cover. The infiltration capacity was moderately fast for the coffee plus alder agroforestry system and moderate for coffee and managed pastures. In general, these results suggest that variables such as organic matter, penetration resistance and apparent density are being affected, to a greater extent by the effect of coverings than by local soil topography conditions, where concave areas, such as those found only for the treatment of grasses, would be favoring a greater content of organic matter, greater thickness of the A horizon, greater porosity and greater gravimetric moisture content. However, this greater porosity (considering that the treatments are on soils with a similar clay-loam texture) is not showing a greater infiltration capacity, due to higher moisture levels favored by the location of the grass cover in an area that tends to become flooded. due to its concave morphometry. These results make it possible to identify water conditions that are more favorable to the recharge of aquifers under agroforestry covers, such as coffee plus alder, and to identify water conditions that are more favorable to coffee agricultural productivity.