Environmental Factors Affecting Agricultural Productivity And Distribution SS2 Agricultural Science Lesson Note

These factors are grouped into three:

1. Climatic factor
2. Biotic factor
3. Edaphic factor

1. CLIMATIC FACTORS AFFECTING AGRICULTURAL PRODUCTION

Climate is the average weather condition of a place over a long period. The elements of climate are rainfall, humidity, light, temperature, drought, wind, sunlight, humidity etc.

i. Rainfall 

Rainfall is defined as the release of excess condensed water vapour in the atmosphere into the earth.

– It determines the distribution of crops and animals.

– It is necessary for seed germination.

– Excessive rainfall leads to leaching.

– It helps to dissolve nutrients, making them available for the plants.

– It determines the types of vegetation in an area.

– It determines seasons in Nigeria.

– Insufficient rainfall causes crop failure and poor yield.

DROUGHT

This is defined as a lack of or insufficient rainfall in the area.

EFFECTS

– It causes delays in flowering and flower abortion.

– Poor crop establishment.

– It leads to a reduction in leaf area.

– It reduces physiological processes due to protoplasm dehydration.

– Decrease in production of green matter.

– Reduction in photosynthesis.

– It causes wilting.

– It causes the death of plants and plant failure.

ii. Temperature

This is the degree of hotness and coldness of a place.

– Temperature is necessary for the germination of seeds.

– It affects the distribution of crops and animals.

– Too hot or too cold temperature does not favour plants and animal growth.

– Unfavorable temperature may result in dormancy. 

– High temperature affects evapotranspiration and reduces the performance of livestock.

– It affects the wilting of field crops, ripening and maturity of crops.

– It affects microbial activities in mineralization.

– High temperature leads to loss of soil minerals by vitalization.

– High temperature causes abortion in farm animals.

– High temperature will cause heat stress and egg drop in poultry.

iii. Wind

Wind is defined as air in motion.

– High wind velocity may cause wind erosion.

– It aids seed and fruit dispersal.

– It can aid pollination and the spread of diseases.

– It helps in the distribution of rainfall and changes in seasons.

– High wind velocity causes damage to crops eg. Lodging.

– It affects evapotranspiration.

iv. Sunlight/sunshine/ Solar Radiation

Sunshine is the amount of heat and the period the sun’s rays are received at a place.

– Sunlight is necessary for photosynthesis. 

– It affects evapotranspiration.

– It affects the productivity of crops due to the length of lay i.e. photoperiodism.

– Light affects the rising and roosting of animals.

– It affects the rate of production in poultry. 

– It determines the productivity of cultivated crops.

– Solar radiation is a source of farm power.

– It assists in the drying of crops.

– It assists in photosynthesis in crops.

– High intensity causes heat stress in animals.

v. Relative Humidity

Relative Humidity is defined as the amount of moisture in the atmosphere.

– It results in the formation of rain.

– It affects the performance of plants and animals.

– It causes mouldiness in the feed and litter.

– Low humidity causes aridity or dryness.

– It determines the type of crops grown in an area.

– Low humidity leads to heat stress in animals e.g. cattle, poultry, and pigs.

– It determines the type of crops grown in an area.

– High humidity favours the growth of pathogens. 

– It affects feed and water intake in animals.

2. BIOTIC FACTORS AFFECTING AGRICULTURAL PRODUCTION

SOIL ORGANISMS

These include bacteria, fungi, earthworms, rodents and termites.

Bacteria and fungi can cause diseases. 

Some aid aeration of soil, percolation and fertility.

Root nodules of bacteria can fix nutrients directly to plants and soil. 

Help in the decomposition of plant materials to form humus.

i. Pests

These include insects, rodents, birds and some mammals.

– They reduce the yield of crops and animals.

– They reduce the quality of crops and animals.

– Some are vectors or carriers of diseases.

– They reduce the income of farmers.

– They increase the cost of production.

ii. Parasites

– They include ticks, liver flukes, tapeworms, dodder, mistletoe and the like.

– Some transit diseases.

– They reduce the quantity or yield of production.

– They reduce the quality of yield. 

– They cause the death of plants and animals.

– They reduce the production capacity of livestock or crops.

The cost of control increases the cost of production.

– They reduce farmers’ income.

3. EDAPHIC FACTORS AFFECTING AGRICULTURAL PRODUCTION

i. SOIL PH

– It affects the growth of plants.

– It also affects the availability of soil nutrients to plants.

– It affects the presence of soil microorganisms.

– It causes toxicity to plants and animals in the soil.

ii. Soil Texture

– It determines the type of soil in an area.

– It determines the level of soil fertility.

– It determines the type of crop to be grown.

– It affects the level of leaching and erosion.

iii. Soil Structure

– It determines the fertility of the soil.

– It determines the water-holding capacity of the soil.

– It determines the level of soil organisms.

– It determines the level of soil aeration and percolation.

iv. Topography

– This is the shape of the land about the underlying rocks of the earth’s surface.

– Steep gentle slopes give rise to soil erosion.

– Steep gentle slopes may also aid the weathering of rocks.

– Even a flat slope can lead to the accumulation of soil.

– Even flat slopes can be better sites for intensive farms.

v  Soil Fertility

– Fertile soils aid the production of food and cash crops. 

– A fertile soil produces better forage crops.

– It minimizes the use of fertilizer.

– It leads to the multiplication of beneficial soil organisms.

– Fertile soil leads to a reduction in the cost of production.

SOIL TYPES

The types include sandy, clay and loamy soil.

Loamy soil is the best for agriculture.

Sandy soil does not contain enough nutrients, hence it cannot support plant growth.

Sandy soil encourages leaching.

Played soil prevents leaching but encourages waterlogging.

ASSIGNMENT

1. The following are climate factors except for (a) soil types (b) humidity (c) temperature (d) light
2. Which of the following is not an edaphic factor (a) soil PH (b) soil fertility (c) soil water (d) topography
3. The following are types of erosion except ____ (a) splash (b) rill (c) sheet (d) mulch
4. The washing away of soil nutrients down beyond the reach of the root is ___ (a) erosion (b) leaching (c) mulching (d) staking
5. High humidity is responsible for ____ (a) dryness (b) water logging (c) rainfall (d) erosion