Leach the soil
ZIMSEC O Level Combined Science Notes: Comparing leaching in soils
Materials: soil samples, distilled water, burners, 3 beakers, measuring cylinders, cotton wool, filter funnel
Method
Boil the filtrate
- Set up the samples as shown in the diagram above
- Pour the same amount of distilled water through each soil sample
- Collect the filtrate
- Evapourate the filtrate completely
- Compare the amount residue left behind by each filtrate
Results
A solid residue is left behind
- The amount of filtrate left by sand soils was the largest when compared to the one left by clay soils
- Loamy soils left a filtrate that is between that of sandy and clay soils in terms of size
Conclusion
- Leaching is greater in sandy soils and the least in clay soil
- The leaching rate of loam soils is in-between that of sand and clay soils
NB This assumes the soils have the roughly the same amount of minerals in them to begin with, sometimes misleading results can obtained if soil samples are collected from outside because sandy soils would have started with less dissolved minerals to begin with since they leach easily
To access more topics go to the Combined Science Notes page.
