Summary

Explains how soil stores and releases water using a simple paper-towel experiment to model soil pores. Introduces the key soil-water stages and connects these ideas to irrigation scheduling terms like available water-holding capacity and management allowable depletion (MAD), and explains why humid regions often use managed depletion irrigation (MDI) to leave room in the soil to capture rainfall. Includes typical water-holding ranges by soil texture and example MAD values for major crops.