Organic matter fractions and microarthropod population in soils under different management and environmental conditions

Abstract

The different fractions of organic matter (<50 m, 50 – 250 m – 2 mm) were quantified in soils along with the population of the different taxa of soil microarthropods (aribatids, actinedids, gamasids and collembola)in two different experiments in 1999 and 2002. The first experiment involved samples from soils under three agroforestry tree species (Dactyladenia bateri, Gliricidia sepium, and Senna siamea) which the second experiment involved samples from soils under eight different environmental and management conditions. The sites included: Calathea plantation, cement factory area, phosphate rock and sand quarry areas, experimental farm, heavily manured vegetable site, and cocoa plantation, all in southwestern Nigeria. In both experiments, the different fractions of soil organic matter (SOM) signifiantly varied among the soils. Population density of the mainly detritivorous microarthropods (Oribatids, gamasids and springtails) under the agroforestry trees were higher where there was higher particulate organic matter of the fraction between 250 m – 2 mm. The oribatid and collembola population densities also correlated positively with same fraction of SOM though collembola population decreased with increasing silt content of soil. Results indicate that particulate organic matter of the fraction between 250 m – 2 mm is more important in stimulating high population of detrivorous microarthropods.

Nigerian Journal of Soil Science Vol. 15 2005: 60-67