CARBON CYCLE
This, is concerned with the way that the atmospheric carbondioxide is utilized by plants and animals and returned to the atmosphere without depleting its volume.
IMPORTANCE OF CARBON CYCLE
LOSS OF CARBON:
(1) Leaching (2) Drainage (3) Photosynthesis (4) Crop removal.
C. WATER CYCLE
This is the continuous circulation of water between the atmosphere and earth.
IMPORTANCE OF WATER TO PLANTS:
(1) Helps in the absorption of mineral salts (2) Essential for plant growth (3) Helps to maintain plant turgidity (4) Helps in the transportation of nutrients to other parts of the plant (5) Helps in cooling of the soil
D. SULPHUR CYCLE
IMPORTANCE OF SULPHUR TO PLANTS:
(1) Member of many plant protein e.g cystine and methionine (2) Also found in plant hormones like Biotin and Theamine (3) Essential for chlorophyll formation:
9.0 EFFECTS OF SOME FARMING PRACTICES ON THE SOIL
9.1 BUSH BURNING: This is setting the bush on fire to destroy the vegetation. Advantages (1) Certain minerals like potassium and phosphorus are released (2) pH of the soil is raised (3) It destroys the seeds of weed (4). The ash released can supply certain minerals and control acidity in the farms (5) It has some sterilizing effects on the soil (6) Destroys soil-borne pathogens or germs. Disadvantages (1) Causes loss of soil organic matter (2) Exposes soil to erosion and leaching (3) Soil structure may be destroyed (4) Leads to loss of soil moisture (5) Volatile soil nutrients are lost e.g nitrogen, sulphur (6) The smoke released causes environmental pollution.
