How Can Apparent Soil Water Retention Capacity Be Analyzed?

This lab activity focuses on determining the water-holding capacity of different soil textures using a simple filtration method. Theoretical background information on soil water retention is provided, including the factors that influence a soil’s ability to hold water, such as soil texture, clay type, organic matter content, and soil structure. The lab exercise involves placing a filter in a funnel above a graduated container, adding 100 mL of soil to the filter, and slowly pouring 100 mL of water on the soil. The water that drains out is collected in the graduated container, and its volume is measured. This procedure is repeated for different soil textures to compare their water-holding capacities. The results are recorded in a table, and the water retention percentage is calculated using a formula. The lab activity highlights the importance of a balance of macro- and micropores in soil for optimum plant growth and explains how organic and inorganic soil amendments can be used to improve water retention.