Another way to collect a stool sample is to loosely place plastic wrap across the rim of the toilet, under the seat. Then place the stool sample in a clean, sealable container before taking to the laboratory. Plastic wrap can also be used to line the diaper of an infant or toddler who is not yet using the toilet. The stool should be collected into clean, dry plastic jars with screw-cap lids.
The potential variations in the properties of agricul-. tural soils are less well known. Diaz et al. (1994) have. reported that under a climate change scenario the soil. organic matter content and erosion rate would de-. crease with regard to current values in the Arrecifes. River basin.
The composition and quantity of microbes in the soil influence the ability of plants to obtain nitrogen and other nutrients. Plant can influence these ecosystem changes through the deposition of root exudates or carbon rich substances into the soil to attract or inhibit the growth of specific organisms.he composition and quantity of microbes in the soil influence the ability of plants to obtain nitrogen and other nutrients. Plant can influence these ecosystem changes through the deposition of root exudates or carbon rich substances into the soil to attract or inhibit the growth of specific organisms.