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The Weight of Water Retained in Unit Area of Soil represents the amount of water that soil can hold against gravity after being saturated and allowed to drain. This is an important parameter in geotechnical engineering and agriculture for understanding soil water retention capacity.
The calculator uses the formula:
Where:
Explanation: The formula calculates the weight of water retained per unit area by multiplying the dry unit weight of soil by the depth of the root zone and the field capacity of water.
Details: Calculating water retention capacity is crucial for irrigation planning, crop water requirements, soil moisture management, and understanding the water-holding characteristics of different soil types.
Tips: Enter the dry unit weight of soil in kN/m³, depth of root zone in meters, and field capacity of water. All values must be positive numbers greater than zero.
Q1: What is field capacity of water?
A: Field capacity is the amount of water remaining in soil after it has been thoroughly saturated and allowed to drain freely, usually for one to two days.
Q2: How does soil type affect water retention?
A: Different soil types have different water retention capacities. Clay soils typically retain more water than sandy soils due to their smaller particle size and higher surface area.
Q3: Why is root zone depth important?
A: Root zone depth determines how deep plant roots can effectively extract water and nutrients, which affects the total water storage capacity available to plants.
Q4: How is dry unit weight of soil measured?
A: Dry unit weight is typically measured by taking a soil sample, drying it completely, and dividing the dry weight by the total volume of the sample.
Q5: What are typical values for field capacity?
A: Field capacity values typically range from 0.1 to 0.4, depending on soil texture, with higher values for clay soils and lower values for sandy soils.