Exercise : Water holding capacity of garden soil and roadside soil
The maximum amount of water retained by soil per unit of its dry weight after the gravitational flow has ceased is called water holding capacity or field capacity of the soil. The water holding capacity varies in different type of soils and depends upon the types of soil particles and porocity of the soil. Sandy soils have poor water holding capacity then the loam and clay soils.
To study the water holding capacity of garden soil and roadside soil.
Garden soil, roadside soil, measuring cylinders, funnels, filter papers, beakers, balance, etc.
Take two funnels and line them with filter paper. Lable them A and B. Place them on measuring cylinders. Take 100 gm dried sample each of the garden soil and roadside soil. Put the garden soil in funnel A and roadside soil in funnel B. Pour 100 ml of water in each funnel. Record the volume of filtered out water in the measuring cylinder when the dripping of water stops from the funnel.
Record the observation in the table as follows:
Garden soil has a high water holding capacity than the roadside soil, because roadside soil has larger quantities of sand and silt.
¬∑ Weighing of soil samples should be done accurately.
¬∑ Pour water slowly and gently on the soil in the funnel
¬∑ Record the volume of collected water in the measuring cylinders carefully.