Erosivity | O Level Notes Agricultural 5038 скачать в хорошем качестве

Erosivity | O Level Notes Agricultural 5038

Erosivity can be defined as the ability of rain to cause erosion. Rain drops loosen soil particles easily. Erodibility is the susceptibility or vulnerability of the soil to erosion. It is affected by texture and structure, topography and land management. Types of erosion There are three types of erosion, namely; sheet erosion, finger erosion and gulley erosion. Sheet erosion takes place on a larger area of thin top soil. Finger erosion makes small tunnels in grazing lands. Gulley erosion results in dongas or gullies being formed. Causes of erosion in arable lands Erosion is cased by the following:  Poor crop cover which leaves top soil vulnerable to the effects of running water.  Ploughing along the slopes which results in an increase in running water speed.  Stream bank cultivation which promotes faster runoff of the soil on steep gradient.  Absence of contour ridges results in more speed and erosive power of running water to carry top soil.  Broken contours allow the water to escape with force through breaks on the contour and washing away soil.  Use of heavy machinery destroys soil structure and the soil becomes susceptible to erosion.  Monoculture. If same crops are continuously grown on the same land, for example sugar cane, they have the effect of loosening the soils resulting in an easy exposure of the soil to erosion.  Burning crop residues. Crop residue acts as ground cover, hence if burned down, the ground is left without cover and erosion takes place. #Erosivity #agricultural