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.
Soil drifting is a fertility-depleting process that can lead to poor crop growth and yield reductions in areas of fields where wind erosion is a recurring problem. Continual drifting of an area gradually causes a textural change in the soil.