In order to evaluate some microbiological and biochemical characteristics, a comparative study was carried out, as related to 3 different land uses in Ultisols located in Grano de Oro, Turrialba, Costa Rica. Three soil management systems were selected (two agroecosystems, coffee and coffee-banana) and forest. In each farm, 4 composite soil samples were collected, on which microbial biomass and respiration, and phosphatase enzyme activity analysis were performed. The microbial biomass in forest was statistically higher (423 mg C kg<span name="style_sup">-1</span>) compared to those in agroecosystems coffee and coffee-banana (77 and 111 mg C kg<span name="style_sup">-1</span> respectively). Microbial respiration did not show differences due to land management (580, 560 and 570 µg CO2 g<span name="style_sup">-1</span>.day<span name="style_sup">-1</span> in coffee, coffee-banana and forest systems, respectively). It was also determined that the enzyme phosphatase activity in forest soils was statistically higher (4432 µg p-NP g<span name="style_sup">-1</span>.h<span name="style_sup">-1</span>). The data suggest that soil conditions in the forest favor greater microbial activity and phosphatase biomass, as compared to agricultural systems.). The data suggest that soil conditions in the forest favor greater microbial activity and phosphatase biomass, as compared to agricultural systems.

Soil respiration; microbial biomass; phosphatase; agroecosystem; forest