CONTENT:

Meaning of Agricultural Ecology

Components of Farm Ecosystem

Interactions Among the Components of Agro-ecosystem

Meaning of agricultural ecology

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

Agricultural Ecology is divided into:

1. Autecology

2. Synecology.

Autecology is 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.

 Synecology is concerned with the study of the inter-relationships between groups of organisms or species of organisms living together in an area. For example, the study of different fish in a fish pond about their aquatic environment.

Ecosystem refers to a community of crop plants and farm animals functioning together with their non-living environment. In other words, the 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 the farm ecosystem

The farm ecosystem is made up of two main components. These are:

1. Biotic (living) components

2. 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 that make use of sunlight or chemicals to manufacture their food from an inorganic substance during the process of photosynthesis. In other words, autotrophs are organisms, mainly crop plants, that are capable of synthesizing their food; hence, they are called producers.

(ii) Heterotrophism: This is a group of organisms, mainly farm animals, which cannot manufacture their 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 components of an ecosystem include the non-living things, which are:

(i) Climatic factors like rainfall, temperature, wind, humidity, and sunlight.

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

(iii) Edaphic factors like soils, rocks, and 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 a short note on primary consumers with relevant examples.
Interaction among the components of the agro-ecosystem in some farm settings
In mono-cropping/sole cropping: Monocropping is a system of cropping where one type of crop is grown on farmland at a particular time. For example oil palm farm, kola nut farm, maize farm, etc. The interaction between the biotic and abiotic factors in the environment include:

1. Crop plants absorb nutrients from the soil to grow.

2. Crop plants also absorb water to grow and produce fruits.

3. Crop plants also take in carbon dioxide from the air to carry out photosynthesis.

In mixed cropping system: Mixed cropping is a system of cropping that 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:

1. Crops like cowpea are capable of adding nutrients to the soil.

2. Crops like cassava obtain nutrients from the soil to grow and produce fruits.

3. The leaves of all crops that fall on the ground decay and add nutrients to the soil through decomposition by soil microorganisms.

In mixed farming, Mixed farming involves the cultivation of crops and the 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 livestock. Their interaction includes:

1. The grasses or the remains of crops serve as food for the animals.
2. The animal dung and droppings are used as organic manure to improve the soil fertility for the crops.
3. 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 the ecosystem in A. mixed farming, mixed cropping C. fish pond.

Theory

1. Write short notes on the two aspects of ecology

2. Explain briefly the interaction among the components of the ecosystem in A. a fish pond, B. a forest/savannah

In our next class, we will be talking about Rock Formation and Types.