Agricultural ecology can simply be defined as a study of the relationships and interactions between crops and animals and their biotic and abiotic components of the environment. Ecology is derived from a Greek word Oikos which means home or dwelling place. In other words, agricultural ecology can be defined as a field of study which details with the relationship of living organisms with one another and with the environment in which they live.
Agricultural ecology is divided into two main branches
Autecology
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 it’s environment.
Synecology
Synecology is concerned with the study of the inter-relationships between groups of organisms are species organisms living together in an area for example, the study of different fishes in a fish pond in relation to the aquatic environment.
Ecosystem
An ecosystem refers to a community of crop plants and a farm animals functioning together with their non-living environment. In other words, ecosystem consists of living factors (plants and animals) interacting with non-living factors in a farm environment. You should be noted that a farm ecosystem is a natural unit in which there is an interaction between all living organisms (called biotic factors) and non-living organisms (called abiotic factors) within a farm environment or habitat.
Components of farm ecosystem
The farm ecosystem is made up of two main components. These are biotic (living) components and the abiotic (non-living) components.
Biotic components
The biotic components include the living things (crop plants and farm animals). The biotic components can be grouped into two classes. These are heterotrophism and autotrophism.
- Autotrophism: This is a group of organisms which can use sunlight or chemicals to manufacture their food from inorganic substance during the process of photosynthesis. In other words, autotrophs are organisms mainly crop plants which are capable of synthesising their own food; hence, they are called producers. Producers are green plants or autotrophs which tribe the energy of sunlight, radiant energy or solar energy and converts it to chemical energy in other to form organic compounds during photosynthesis using carbon dioxide and water or simple inorganic substance as raw materials. Producers or autotrophs provide food for the other organisms in the farm.
- Heterotrophism: Heterotrophism is a group of organisms mainly farm animals, which cannot manufacture their own food but depend directly or indirectly on plants of 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 while animals or organisms that feed on the primary consumers are called carnivores or secondary consumers. Animals that feed on the secondary consumers are called tertiary consumers. Heterotrophism include all farm animals, fungi and some bacteria.
Abiotic components
The abiotic components of an ecosystem include the nonliving things which are:
- Climate factors like temperature, wind, humidity, sunlight and rainfall.
- Inorganic materials are nutrients such as carbon dioxide, oxygen, nitrogen, calcium, phosphorus.
- Edaphic factors like soils, rocks and topography.
- Other factors like dust, storm, fire and water.
General interaction among the components of ecosystem
There is a unique interaction among the various components of ecosystem. Green crop plants use carbon dioxide, water and chlorophyll in the presence of sunlight to produce carbohydrates or starch. Farm animals feed on this carbohydrates or plants and release carbon dioxide for crop plants to take it. Micro-organisms an other decomposers break down dead plants and animal dungs to release nutrients to the soil. This nutrients are absorbed by plants for use in food production. Coral plants give out oxygen during photosynthesis which is used by animals for their normal respiration.
Interactions among the components of agro-ecosystem in some farm settings
In mono or sole cropping system
Monocropping is a system of cropping where one type crop is grown on a farm or the same piece of land at the same time. Monocropping is usually practice on large scale farms, where crops such as oil palm, cocoa, kolanut, rubber, rice, maize, etc are grown.
The interactions between the biotic and the abiotic factors in the environment s are as follows
- Crop plants absorb nutrients from the soil to grow.
- Crop plants also absorb carbon dioxide from the air to carry out photosynthesis.
- Crop plants also absorb water to grow and produce fruits.
- Crop residues decay and with the head of soil micro-organisms release nutrients to the soil.
- Some organisms in the soil like earthworms and rodents also aid water percolation.
- Crop plants also reduce oxygen to the atmosphere during respiration.
In mixed cropping system
Mixed cropping system is a system of cropping which involves the growing of two or more crops on the same piece of land at the same time, during the same growing season. The crops are mixed together on the same piece of land. Crops like maize, cassava, cowpea, etc. can the cultivated at the same time on the same piece of land.
The interactions between the biotic and the abiotic factors in the environment are as follows
- Crop like cowpea accountable of adding nutrients to the soil.
- Crops plants like cassava obtain nutrients from the soil to grow and produce fruits.
- Crop plants also release carbon dioxide into the atmosphere during respiration.
- Farm animals can feed on this crops and release faeces or dungs on the ground which leather decay to release nutrients to the soil.
- The leaves of all the crops which fall on the ground decay and add nutrients to the soil through decomposition by soil-microorganisms.
- Oxygen is also released to the atmosphere by the crop plants during photosynthesis.
- Carbon dioxide from the air is absorbed by the crop plants to manufacture their food through the process of photosynthesis..
In mixed farming
Mixed farming involves the cultivation of crops and rearing of animals simultaneously on the same piece of land or farm. The farm may be divided into parts. One part for growing crops and the other parts for growing of grasses and keeping of livestocks.
The interactions between the biotic and abiotic factors in the environment are as follows
- 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.
- Both animals and crops releases carbon dioxide to the atmosphere during respiration.
- Some crops like cow pear and crop residue may decay to release nutrients to the soil.
- Crop plants absorb so any trends and water from the soil for growth and production.
- Crop plants can also release oxygen to atmosphere during the process of photosynthesis.
- Crop plants also make use of sunlight in the environment to make the food through the process of photosynthesis.
In fish pond
Fish pond is an aquatic environment where fishes live, grow, produce and are harvested for food and other commercial purposes.
The interactions between the biotic and abiotic factors in the aquatic environment include the following
- The fishes feed on planktons in the water as their source of food.
- The death of some fishes serves as Man u for the microscopic plants (planktons) in the water.
- Both planktons and fishes release carbon dioxide to the aquatic habitat which aids photosynthesis by the planktons.
- Fish dungs or droppings how to provide a source of nutrients to the planktons in the water.
- The planktons also make use of sunlight during photosynthesis to manufacture their food.
- The planktons in the water make use of carbon dioxide and water to make their food and release oxygen to the environment which aids respiration in water.
In the forest or savanna
The forest or the savanna is a large expanse off land containing varieties of plants and animals living and interacting together in a terrestrial environment.
The interactions between the biotic and abiotic factors in a terrestrial (forest or savanna) environment are as follows
- Animals feed on plants and fruits to obtain their food.
- Animals dungs and droppings can serve as nutrients to the soil.
- Plants obtain the nutrients and water from the soil to enable them prepare their food.
- Plants generally the needs oxygen into the environment during photosynthesis.
- Sunlight from the atmosphere is also used by green plants to manufacture their food during photosynthesis.
- Plants and animals also respire to release carbon dioxide to the environment which is used by plants to manufacture their food.