Caracterización de la fertilidad del suelo en monocultivos de cafe (Coffea Arabica) y bajo sombrio de guamo (Inga ssp)

Abstract

The properties of the soils and cycle of nutriments in cultivations of coffee with Inga spp shade and free exhibition were characterized in 8 units of soil of 7 departments, selecting lots for the two systems. In each cultivation three soil samples were taken for each depth: 0-5, 5-10, 10-15, 15-20, 20-30 and 30-40 cm. The cycle of nutrients was evaluated in two of the locations. The biggest differences among agroecosystems were registered for the physical properties, mainly in the first 10 cm. The soils cultivated with shade had lowest bulk density and temperature, as well as higher porosity and humidity than the soils cultivated without shade, at the same time they exhibited the lowest values of compression. The establishment of shade with Inga contributed in the conservation and the improvement of some properties of the soil; the produced effect was determined in great measúrby the organic matter. The return of organic máterial in cultivations with shade (11,2 and 10,5 tn.ha - 1\ was 2,5 times highest than a cómplete exposition to the sun (4,6 and 4,2 tn.ha-'), and with a higher amount ofnutriments. The annual rate of decomposition of the Inga was the lowest, 0,58 in El Cairo and 0,85 in Chinchiná, while for coffee the variation was 1,39 and 1,70. The microbial activity presented different behavior through the time among locations, this value being bigger for coffee exposed to the sun in one of the places.