Geography & History Notes | KCSE, NECTA, ZIMSEC & GCSE

  Soil Degeneration is the Decline in the usefulness of a soil . Types of soil degeneration Physical soil degeneration This is a Decline in the use of soil in which texture, structure, moisture, and quality of soil are affected. causes of physical soil degeneration Deforestation which leads to the removal of vegetation which forms a protective cover of the soil exposing it to erosion agents. Overgrazing which causes excessive loss of water from the soil causing it to become loose and fine-grained and easily eroded. Poor Cultivation Techniques i) Pulling hoe along the surface when removing weeds which loosen the soil and when it rains its washed away. ii) Ploughing of land downslope which accelerates soil erosion . iii)Cultivation of steep slopes and along river banks which encourages soil erosion. iv) Burning which destroys vegetation covering the soil exposing it to erosion agents. v) Growing crops on the same piece of land from season to season sucks nutrients from the soil mak...

  The recovering of land that has been rendered unsuitable for use to make it usable again Or Is the process of turning the poor land into a useful state through the improvement practices for economic and social development. The main aims of land reclamation are as follows;- To increase the size of land available for agriculture purposes. This was carried out in the Tennessee valley. Previously unused land was irrigated in order to increase crop production. To increase the size of land available for human settlement. This may become necessary if the population of an area grows beyond the land is available. It may also create land to resettle people who are being moved from another area. To make available more land for the establishment of industries and offices. To be in proximity to resources in order to be able to gainfully utilize them. RELATED POSTS IMPORTANCE OF SOIL STRUCTURE     7 CHARACTERISTICS OF EQUATORIAL CLIMATE    7 ADVANTAGES OF WETLANDS ...

  Soil erosion is wearing away of soil particle due to action of erosion agents such as moving water, ice and wind.Erosion, whether it is by water, wind or tillage. Soil erosion involves three distinct actions – soil detachment, movement and deposition. Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere "on-site" where it builds up over time or is carried "off-site" where it fills in drainage channels.  Soil erosion reduces cropland productivity and contributes to the pollution of adjacent watercourses, wetlands and lakes. water erosion is the result of rain detaching and transporting vulnerable soil, either directly by means of of rain splash or indirectly by rill or gully erosion The following are forms of water erosion Rain drop or splash erosion Erosion preceded by the destruction of the crumb structure due to the impact of falling raindrop on the surface of soil is termed as splash erosion. Sheet erosion It is the fairl...

  The following are Soil Conservation methods Crop rotation This is the planting of different crops on the same piece of land. it can also be defined as the movement of crops from site to site on the farm in a planned sequence This helps to control monoculture and its effects. advantages of crop rotation it interrupts pest-host cycles and prevent the buldup of pests weed and pathogens. it allows crops to access nutrients from different soil depths basing on their rooting characteristics intergrating cover crops and fallow periods into rotation help build soil organic matter and improve aggregation Afforestation and re-afforestation here, trees are planted in areas where they have been cleared or areas where trees have never been planted. The planted trees help in controlling the effects of heavy raindrops and the speed of the wind, which are major agents of erosion . Mulching This is the covering of soil with different materials e.g. grass so that it can be able to store moisture i...