Biotic Factors Or Biological Factors Affecting Crops And Animal Production

What is Biotic and Abiotic factor?

Biotic Factors Or Biological Factors Affecting Crops And Animal Production

1. PREDATORS:           These are living organisms that prey or feed on other organisms. Examples are birds, rodents, insects, etc. Some are beneficial and some destructive.   Some control harmful pests of crop and animals, others feed on other animals e.g. hawk etc.

2.PARASITES (PARASITISM): A parasite is an organism which lives on or in another living organism known as the host. It obtains its food from the body of its living host. Often, a parasite harms its host by causing diseases or death.

TYPES OF PARASITES

1. ENDOPARASITE: – These are parasites which live inside or within the body of other animals. e.g. liver fluke, tapeworm, roundworm or ascaris.
2. ECTOPARASITE: – Parasites that live outside or on the host. Example tick,  lice, mites, insect bugs, fleas, etc.

3. SOIL ORGANISM: Soil organism can be classified into micro organism or macro organism.

Microorganisms are bacteria, virus etc, while macro organisms are rodents, termite, centipedes etc. Some like bacteria and fungi can cause disease, some aid aeration in soil, hence improving soil fertility. Some like root nodule bacteria can fix nutrients directly to plant and soils. Some help in the decomposition of plant and animal material to form humus.

4. PESTS: These organisms cause damage or destroy crops either in the field or in stores. They include insect, rodents, birds and some animal e.g. monkeys. They reduce the yield of crops and animals thereby reducing the farmer’s income. Some are vectors or carriers of diseases .The cost of their control increases the cost of production.

EVALUATION QUESTIONS

1          What are pests?

2          State five examples of pest.

5. DISEASES

Disease is a situation in plants or animals in which there is a deviation of the plant or animal from normal state of health. Disease can be caused by pathogens which are virus, bacteria, fungi, protozoa etc. They cause reduction in the yield of crops and animals. They can cause loss or death of plants and animals. The cost of control increases the cost of production which affects the income of the farmers.

6. MUTUALISM (SYMBIOSIS)

In mutualism, two organisms live together for the mutual benefit of each other. Termites and the protozoa living in their guts are mutualistic. The protozoa receive protection from termites; it helps in the breakdown of food in termites. The protozoa help them to digest it.

7. WEEDS: They compete with crops for space, water, nutrients and sunlight. Some may harbour diseases and pest. They reduce the yield of crops. The control increases the cost of production.

EDAPHIC FACTORS OR PHYSICAL FACTORS

1          SOIL pH: This is the degree of acidity or alkalinity of a soil.

1. It affects the growth of plant.
2. It affects the availability of soil nutrients to plant.
3.  It affects the presence of soil micro-organisms

2          SOIL TEXTURE: This is the measure of fineness or coarseness of soil samples. 

1. It determines the type of soil in an area.
2. It determines the level of soil fertility.
3. It determines the type of crops to be grown.
4. It affects the level of leaching and erosion of the soil.

3          SOIL STRUCTURE: This is the physical appearance of the soil according to the way individual particles are packed or arranged.

1. It determines the fertility of the soil.
2. It determines the water retaining capacity of the soil
3. It determines the level of aeration.
4. It determines the level of micro-organism

GENERAL EVALUATION/REVISION QUESTIONS

1.         What is soil structure?

2.         Define soil texture.

3.         What is soil pH?

4.         State three features of soil texture

5.         List out any five soil organisms

READING ASSIGNMENT

Read Pasture and forage crops from Essential Agriculture by O.A. Iwena pages 179-182.

WEEKEND ASSIGNMENT(WK 9B)

1. Which of the following is not an edaphic factor affecting agricultural production? A. Soil pH       B. soil texture     C. soil organic              D. soil type
2. Plant and animal remains allowed to decay in the heap is referred to as. A. Farmyard manure   B. compost     C. green manure         D. inorganic manure
3. Which of the following is a primary product of forest trees?   A. Pulp  B. timber

C. paper D. cardboard.

• Which of the following practices can prevent excessive evaporation from soil surfaces?           A. mulching     B. weeding      C. harrowing   D.ploughing
• The appearance of the soil according to the way individual particles are packed or arranged is called A. soil structure       B. soil texture C. soil pH D. soil profile
• The following are endo-parasites of livestock except A. roundworm B. tapeworm

C. liver fluke                     D. earthworm.

THEORY

1)         Discuss briefly five biotic factors that affect crops and animals distribution.

2)         State three edaphic factors affecting crops and animals distribution.