Soil strength

Soil strength is defined as the amount of force required to move or rearrange soil particles.

7.1 Factors affecting soil strength

(1) Moisture content

                   When soils are saturated or waterlogged, soils are relatively weaker, therefore, soils can be easily broken down.

                   Soils cannot be easily broken down because of dry conditions. Therefore these soils are more strength.

(2) Bulk density

                   When soils have low bulk density, these soils can be easily broken down because these soils consist of relatively more pores so mass per unit volume is relatively low. Therefore soil can be easily broken down.

                  Soils cannot be easily broken down because when the soil has a high bulk density that’s mean, the soil has relatively lower pores so mass per unit volume is relatively high.

(3) Structure

                When soils are well aggregated like clay soils, the soils have relatively larger strength. Sands, sandy loams and loamy sands have relatively smaller strength because these soils aren’t well aggregated.

                 7.2 Importance of soil strength

                               1) Germination of seeds

                               2) Plant growth

                   Good aeration and well-drained of soils are essential for the germination of seeds and the growth of plants.

        7.3 Human effects on soil strength

                  Soil management practices for agriculture are affected by soil strength badly. Compacted soil horizons called Ap or E are formed due to the using of heavy machines for tillage practices. Compacted soils have usually higher strength, therefore, the growth of plants and The germination of seeds is restricted.

          7.4 Measuring of soil strength penetrometers

                Penetrometers are used to measure soil strength. A rod is entered into the soil by inserting force that the required force is used to measure the soil strength.  Therefore we can recognize the affection of compaction soils to the growth of plant and germination of seeds by resistance to the exert of a rod into the soil.