Agricultural Ecology, Farm Ecosystem and Agro-ecosystem

CONTENT

• Meaning of Agricultural Ecology
• Components of Farm Ecosystem
• Interactions Among the Components of Agro-ecosysytem

MEANING OF AGRICULTURAL ECOLOGY

Agricultural Ecology is defined as the study of crop plants and farm animals in relation to their environment. Ecology is derived from a Greek word “Oikos” which means home or dwelling place. In order words, agricultural ecology can be defined as a field of study which deals with the relationship of living organisms with one another and with the environment in which they live.

Agricultural Ecology is divided into:

A.  Autecology

B.Synecology.

Autecologyis concerned with the study of an individual organism, or a single species of organism and its environment. For example the study of a single cattle and its environment.

Synecologyis concerned with the study ofthe inter-relationshipsbetween groups of organisms or species of organisms living together in an area. For example the study of different fishes in a fish pond in relation to their aquatic environment.

Ecosystem refers to a community of crop plants and farm animals functioningtogether with their non-living environment. In other words, ecosystem consists of living factors(plants and animals) interacting with the non-living factors in a farm environment.

EVALUATION

1. What is Agricultural Ecology?
2. Write short notes on the two aspects of ecology.
3. Define ecosystem.

COMPONENTS OF FARM ECOSYSTEM

The farm ecosystem is madeup of two maincomponents. These are:

• Biotic (living) components
  • Abiotic (non-living) components

BIOTIC COMPONENTS: The biotic components include the living things i.e. crop plants and farm animals. The biotic components can be grouped into two classes which are; Autotrophism and Heterotrophism.

(i) Autotrophism: This is a group of organisms which makes use of sunlight or chemicals to manufacture their foodfrom inorganic substance during the process of photosynthesis. In other words, autotrophs are organisms mainly crop plants which are capable of synthesizing their own food, hence they are called producers.

(ii) Heterotrophism: This is a group of organisms mainly farm animals which cannot manufacture their own food but depend directly or indirectly on plants for their food, hence they are called consumers. Farm animals that feed directly on green plants (producers) are called herbivores or primary consumers e.g. cattle, sheep, goat and rabbit.

ABIOTIC COMPONENTS:The abiotic componentsof an ecosysteminclude the non-living things which are:

• Climatic factors like rainfall, temperature, wind, humidity and sunlight.

(ii) Inorganic materials and nutrients such as carbondioxide, oxygen, nitrogen, calcium and phosphorus.

(iii) Edaphic factors like soils, rocks, topography.

(iv) Other factors like dust, storm, fire and water.

EVALUATION

1. Differentiate between autotrophs and heterotrophs.

2. State five examples of climatic factors.

3. Write short note on primary consumers with relevant examples.

INTERACTION AMONG THE COMPONENTS OF AGRO-ECOSYSTEM IN SOME FARM SETTINGS

• In Mono-cropping/Sole Cropping: Mono-cropping is a system of cropping where one type of crop is grown on a farmland at a particular time. For example oil palm farm, kolanut farm, maize farm, etc. The interaction between the biotic and abiotic factors in the environment include:
• Crop plants absorb nutrients from the soil to grow.
• Crop plants also absorb water to grow and produce fruits.
• Crop plants also take in carbondioxide from the air to carry out photosynthesis.
• In Mixed Cropping System:Mixed cropping is a system of cropping which involves the growing of two or more crops on the same piece of land at the same time. Crops like maize, cassava, cowpea etc can be cultivated at the same time on the same farmland. Their interactions include:
• Crops like cowpea is capable of adding nutrients to the soil.
• Crops like cassava obtain nutrients from the soil to grow and produce fruits.
• The leaves of all crops which fall on the ground,decayed and add nutrients to the soil through decomposition by soil microorganisms.
• In Mixed Farming: Mixed farming involves the cultivation of crops and rearing of animals simultaneously on the same piece of farmland. The farm may be divided into two parts: one part for growing crops and the other for growing grasses and keeping of livestock. Their interaction include:
• The grasses or the remains of crops serve as food for the animals.
• The animal dungs and droppings are used as organic manure to improve the soil fertility for the crops.
• Some crops like cowpea and crop residue may decay to release nutrients to the soil.

GENERAL EVALUATION

1. What is Agricultural Ecology?
2. Write short notes on the two aspects of ecology.
3. Define ecosystem.
4. State five examples of climatic factors
5. Explain briefly the interaction among the components of ecosystem in: A. mixed farming  B. mixed cropping C. fish pond.

READING ASSIGNMENT

Essential Agricultural Science by O.A. Iwena, pages 37-40

WEEKEND ASSIGNMENT

1. All these farm animals are polygastric animals except  A. cattle  B. goat  C. rabbit 

D. sheep

• The branch of ecology which deals with the study of a single speciesof organism and its interaction with the environment is known as… A. autecology  B. synecology 

C. entomology  D. pathology

• Climatic factors include the following except… A. wind  B. sunlight  C. rocks  D. rainfall
• ….. involves the cultivation of crops and rearing of animals simultaneously on the same piece of farmland. A. Mixed cropping  B. Mixed farming  C. Bushfallowing  D. Pastoral farming
• The animal dungs and droppings are used as ………to improve the soil fertility for the crops. A. inorganic manure  B. organic manure  C. moisture  D. mulch

THEORY

1. Write short notes on the two aspects of ecology
2. Explain briefly the interaction among the components of ecosystem in: A. a fish pond B.a forest/savannah