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

  soil water is water available for consumption by plants . Soil water has been classified from a physical and biological point of view as Physical classification of soil water, and biological classification of soil water.   Physical classification of soil water Gravitational water Gravitational water occupies the larger soil pores (macro pores) and moves down readily under the force of gravity. Water in excess of the field capacity is termed gravitational water. Gravitational water is of no use to plants because it occupies the larger pores. It reduces aeration in the soil. Thus, its removal from soil is a requisite for optimum plant growth. Soil moisture tension at gravitational state is zero or less than 1/3 atmosphere. Factors affecting gravitational water Texture: Plays a great role in controlling the rate of movement of gravitational water. The flow of water is proportional to the size of particles. The bigger the particle, the more rapid is the flow or movement. B...

  Leaching is removal of materials in solution or suspension downwards as water move vertically through the soil body by force of gravity. Leaching results into movements of soluble and suspended materials in water percolation. Leaching involves two forms: Elluviation - which is washing out of materials in solution or suspension from the overlying parts of the soil body; and  Illuviation - which is accumulation of materials taken from the overlying parts of the soil body. RELATED POSTS 9 CONDITIONS FAVOURING IRRIGATION FARMING IN EGYPT 5 CAUSES OF RURAL-RURAL MIGRATION IN KENYA 10 AIMS OF KILOMBERO VALLEY IRRIGATION SCHEME 4 FEATURES OF MAP STATEMENT SCALE 10 ADVANTAGES OF OIL PRODUCTION IN THE MIDDLE EAST 7 DISADVANTAGES OF AIR TRANSPORT 10 PROBLEMS FACING COFFEE FARMING IN KENYA IMPACTS OF POVERTY ON ENVIRONMENT 10 PROBLEMS FACING COTTON FARMING IN UGANDA COMPARISON BETWEEN FISHING IN KENYA AND JAPAN

  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...

  Soil is the mixture of minerals, organic matter, gases, liquids, and the countless organisms that together support life on Earth. Soil composition is an important aspect of nutrient management. While soil minerals and organic matter hold and store nutrients, soil water is what readily provides nutrients for plant uptake. Soil air, too, plays an integral role since many of the microorganisms that live in the soil need air to undergo the biological processes that release additional nutrients into the soil. Soil is composed of both organic and inorganic matter, and it is essential for life on earth to exist.  Soil is composed of: Mineral Particles: Mineral particles are the largest ingredient and make up approx 45% of soils . They are the original rock that got broken down by weathering and erosion to form the basis of soil. The type of rock that was broken down to form it is called the parent rock. The broken down rock produces minerals such as calcium, phosphorus, and potas...