Role of soil structure in relation to plant growth
Soil structure influences the amount and nature of porosity.
Structure controls the amount of water and air present in the soil. Not only the amount of water and air dependent on soil structure, but their movement and circulation are also controlled by soil structure.
It affects tillage practices.
Structure controls runoff and erosion.
Platy structure normally hinders free drainage whereas sphere like structure (granular and crumby) helps in drainage.
Crumby and granular structure provides optimum infiltration, water holding capacity, aeration and drainage. It also provides good habitat for microorganisms and supply of nutrients.
Class of Soil Structure as differentiated by size of soil peds
| Class | Platy | Prism-atic | Colum-nar | Blocky | S.A. Blocky | Gran-ular | Crumb |
V.Fine or V.Thin | <1 | <10 | <10 | <5 | <5 | <1 | <1 |
Fine or Thin | 1-2 | 10-20 | 10-20 | 5-10 | 5-10 | 1-2 | 1-2 |
Medi | 2-5 | 20-50 | 20-50 | 10-20 | 10-20 | 2-5 | 2-5 |
um | 5-10 | 50-100 | 50-100 | 20-50 | 20-50 | 5-10 | – |
Coarseor Thick | >10 | >100 | >100 | >50 | >50 | >10 | – |
V.C | >10 | >100 | >100 | >50 | >50 | >10 | – |
or V.Thic |