1 of 5

Estimating Soil Moisture by Feel and Appearance

Unit: Soil Science Lesson 6

2 of 5

Objectives

  • Define: irrigation water management, available water capacity, percent available, soil moisture deficit, in/ft depleted
  • Explain the significance of irrigation water management
  • Explain key factors that impact observations made in the feel and appearance method
  • Differentiate between percent available water capacities in different soil types
  • Obtain a soil sample using a probe, auger or shovel
  • Squeeze the soil sample firmly to form an irregularly shaped “ball” of soil
  • Squeeze the soil sample out of the hand between the thumb and forefinger to form a soil “ribbon”
  • Observe the soil texture, ability to ribbon, firmness and surface roughness, water glistening, loose soil particles, soil/water staining on fingers and soil color
  • Compare observations with photographs and/or charts to estimate percent water available

3 of 5

Define

  • Irrigation water management: is applying water according to crop needs in an amount that can be stored in the plant root zone of the soil.
  • Available water capacity: is the amount of water that a soil can store that is available for use by plants
  • Percent available: currently available soil moisture as a percent of available water capacity
  • Soil moisture deficit: is the amount of water in a soil that can be readily absorbed by plant toots of most crops
  • in/ft depleted: Inches of water currently needed to refill a foot of soil to field capacity

4 of 5

Why is it important to properly manage irrigation water?

5 of 5

Irrigation water management determines:

  • How much water is available for plant use
  • When to irrigate
  • How much irrigation water to apply
  • Soil and irrigation water conservation