Could You Explain How Sandy And Clayey Soils Can Be Improved?

The properties of both sandy and clayey soils are quite different from each other. Therefore to improve the soil, different methods are used.
Sandy soil can be improved by:
1.Addition of humus, e.g. farmyard manure (cow dung, organic refuse etc.) which improves the texture by filling up the air spaces so that water will not drain away easily. Manure also improves the capillary action (originally sandy soils have a low capillary action), aids water retention, and enriches the soil with mineral salts, especially nitrates, phosphates and potassium salts.
2.Addition of clay, this is not a feasible on a large scale.

Clayey soils can be improved by:
1.Addition of chalk (lime): this causes flocculation (adhesion of smaller particles to form larger ones). It improves the texture by "opening up" the soil, hence improving aeration and preventing water logging. Lime also checks the acidity in the soil and provides calcium ions for plant growth.
2.Addition of humus: this also improves the texture of the soil and makes it less heavy. It forms soil crumbs, improving aeration and drainage. It increases the mineral salts content of the soil.
3.Mixing with sand: This is not feasible on a large scale.