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

  Soil organic matter (SOM) is the organic matter component of soil, consisting of plant and animal residues at various stages of decomposition, cells, and tissues of soil organisms, and substances synthesized by soil organisms. The following are factors affecting decomposition of soil organic matters: Temperature: Cold periods retard plant growth and OM decomposition. Warm summers may permit plant growth and humus accumulation.  Soil moisture: Extremes of both arid and anaerobic conditions reduce plant growth and microbial decomposition. Near or slightly wetter than field capacity moisture conditions are most favourable for both processes.   Nutrients: Lack of nutrients particularly N slows decomposition.   Soil PH: Most of the microbes grow best at pH 6 – 8, but are severely inhibited below pH 4.5 and above pH 8.5.   Soil Texture: Soils higher in clays tend to retain larger amounts of humus.   Other Factors: Toxic levels of elements (A...

humification is the process by which the remains of died organisms of both animals and plants accumulate, decompose and mix with soil to form humus in the soil body. the process is mainly done by soil living organisms. it is one of the important process in soil formation as it makes soil to have humus, which is one of soil component. this process occur rapidly in tropical humid areas but it take place gradually in cool regions.    RELATED POSTS IMPORTANCE OF SOIL STRUCTURE     7 CHARACTERISTICS OF EQUATORIAL CLIMATE    7 ADVANTAGES OF WETLANDS     7 FACTORS INFLUENCING MASS WASTING    5 CONDITIONS FOR EXISTENCE OF CORAL REEFS    3 TYPES OF WEATHERING AND THEIR PROCESSES    6 LANDFORMS OF HIGHLANDS GLACIATION CAUSES AND EFFECTS OF OCEAN BREEZE AND SEA BREEZE PLATE TECTONICS THEORY EXPLAINED 9 CHARACTERISTICS OF COMMERCIAL LIVESTOCK FARMING Characteristics of tropical northern climate 12 FACTORS THAT FAV...

  Soil organic matter are remains of dead living things that is dead animals and plants. Decaying of dead living things which leads to formation of soil organic matter, is affected by number of factors as we will explain below. Therefore without further a due the following are factors which affect the formation of soil organic matters :    Climate: Temperature and rainfall exert a dominant influence on the amounts of nutrients and Organic matter found in soils. Temperature: The Organic Matter content of comparable soils tend to increase if one moves from warmer to cooler areas. The decomposition of Organic matter is accelerated in warm climates as compared to cooler climates. For each 10 C decline in mean annual temperature, the total Organic matter and nutrients increases by two to three times.  Rainfall: There is an increase in Organic Matter with an increase in rainfall. Under comparable conditions, the Organic matter increase as the effective moisture beco...