How Climatic Factors Affect Crop Production (Plant Growth)

March 7, 2024March 7, 2024 Agric4Profits

Crop production (plant growth) are often affected by climatic factors like rainfall, temperature, humidity, etc. They are also the important aspects of the physical environment that notably influence all aspects of agricultural production.

However, climatic factors such as rainfall and temperature exhibit seasonal variations, and these are not only critical in determining the cropping patterns and systems, but also critical in determining the length of the growing season.

These, in addition to the influence of climate on the occurrence of rain and crop physiological growth, ultimately determine the magnitude of the yields of cultivated crops in the different ecological zones around the world.

Agriculture always faces the risks due to various reasons. Among that climatic risks are the most important one as there are unavoidable and unexpected.

Increased temperature, changed precipitation conditions and increased CO2 content in the atmosphere are the major climatic factors affecting plant growth and crop production. Rise in atmospheric temperature will lead to loss of soil moisture and will increase the crop demand for water.

The amount and availability of water stored in the soil will be affected by changes in both the precipitation and seasonal and annual evapotranspiration regimes.

Changes in atmospheric carbon dioxide concentration can cause uncertainty in crop yields. Solar radiation also has considerable effect on photosynthesis and crop yield.

The effect of interrelationship between the climatic factors like temperature, rainfall, solar radiation, CO2 concentration, etc. and crop yield need to be understood to take necessary adaptation measures to maintain the crop production.

Climatic Factors that Affect Plant Growth and Crop Production

How Climatic Factors Affect Crop Production (Plant growth)

Below are the major climatic factors the affects crop production services:

1. Rainfall

Rainfall is the most common form of precipitation. It is the falling of water in droplets on the surface of the Earth from clouds. Other forms of precipitation are freezing rain, sleet or ice pellets, snowfall, and hail.

The amount and regularity of rainfall vary with location and climate types and affect the dominance of certain types of vegetation as well as crop growth and yield.

Rainfall is regarded as the most important climatic variable and it has a far-reaching influence on agricultural crop production as it plays the following roles in agricultural production:

1. It is the main source of moisture supply to the soil for the activation of plant growth (plant growth 5e, 5e plant growth, plant growth regulators, plant growth stages).

2. It replenishes the water in rivers to allow irrigation operation.

3. It builds up underground water reserves which are later tapped by wells in the dry areas through seepage and percolation.

4. Rainfall also influences the soil/water/plant relationships; soil moisture status has significant direct relevance for plant growth because water balance = total rainfall – (run-off + evapotranspiration).

The amount, incidence, variation, and reliability of rainfall, therefore, determine the differences in cropping patterns in various ecological zones around the world.

2. Temperature

Temperature is one of the major factors limiting the distribution of plants and animals on a global scale. It is of secondary importance in influencing evapotranspiration, photosynthesis, and soil warming.

The degree of hotness or coldness of a substance is called temperature. It is commonly expressed in degree Celsius or centigrade (C) and degree Fahrenheit (F).

This climatic factor influences all plant growth processes such as photosynthesis, respiration, transpiration, breaking of seed dormancy, seed germination, protein synthesis, and translocation.

Some of the known effects of temperature on the farming system include:

1. Rapid soil organic matter (SOM) decomposition due to high microbial activities and increased rates of biochemical reactions.

2. Effects on plant life process such as seed germination, pollination, flowering, fruiting, ion uptake, leaf growth, and cell enlargement.

3. High temperatures render built-in fallows ineffective and enhance the incidence of pathogens and pests.

4. High night temperatures favor high respiratory rates and exhaustion of plant assimilates, resulting in low net assimilate accumulation and poor crop yield.

Soil temperatures are more important to plant growth than air temperatures. However, air temperatures are not limiting to crop growth, thus variations in regional and seasonal distribution are of local importance to agriculture.

Farmers have to adapt to these problems and control them through the following practices:

Early crop harvesting;
Mixed cropping;
Mulching;
High nutrient supply;
Organic matter supply in decaying residue;
Minimizing run-off/erosion;
Protection and shading of the soil;
Suppression of weed growth.

3. Winds and Ocean Currents

These climatic variables strongly influence rainfall occurrence and duration of the rainy season. Other winds of great importance to agricultural production include sea breezes, land breezes, and ocean currents.

The ocean currents are divided into three namely; the Cold Benguella current, Guinea counter-current, and the Cool Canary current. The currents influence climatic conditions through the winds blowing over an area.

Winds blowing over a warm current are usually moisture-laden while those blowing over a cold current usually have a cooling effect on the coast arising to the formation of fog instead of rain.

The oxygen and carbon dioxide in the air is of particular importance to the physiology of plants. Oxygen is essential in respiration for the production of energy that is utilized in various growth and development processes. Carbon dioxide is a raw material in photosynthesis.

The air also consists of suspended particles of dust and chemical air pollutants such as carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2), sulfur trioxide (SO3), nitrogen oxides, methane (CH4), propane, chlorofluorocarbons (CFCs), solid particles of dust, soot, asbestos and lead, ozone and many more.

4. Relative Humidity

This can be described as the ratio between the amount of water vapor held in the air and the maximum possible amount that can be held at a particular temperature. It is a measure of the dampness of the atmosphere.

High relative humidity increases disease incidence on cropped farms and reduces the crop’s ability to intercept solar radiation. Contrarily, low relative humidity leads to high evapotranspiration and transpiration which eventually cause wilting of crop stands.

For example, an air having a relative humidity of 60% at 27 C temperature means that every kilogram of the air contains 60% of the maximum amount of water that it can hold at that temperature (Miller 2001).

The amount of water vapor in the air ranges from 0.01% by volume at the frigid poles to 5% in the humid tropics. In relation to each other, high RH means that the air is moist while air with minimal content of moisture is described as dry air. Compared to dry air, moist air has a higher relative humidity with relatively large amounts of water vapor per unit volume of air.

The relative humidity affects the opening and closing of the stomata which regulates the loss of water from the plant through transpiration as well as photosynthesis.

A substantial understanding of this climatic factor is likewise important in plant propagation. Newly collected plant cuttings and bareroot seedlings are protected against desiccation by enclosing them in a sealed plastic bag.

The propagation chamber and plastic tent are also commonly used in propagating stem and leaf cuttings to ensure a condition with high relative humidity.

5. Day-length/Photo-period

This indicates the length or duration of sunlight hours per day. It is variable due to the apparent movement of the sum either in the northern or the southern hemisphere.

These trends also affect wind movement and rainfall occurrence. Daylight affects flowering and tuber formation, vegetative development, seed germination (e.g. some rice and soybean varieties that are sensitive to photo-period), and timing of agricultural operations such as planting, harvesting, and type of crops to plant.

Based on photo-period, there are three groups of plants namely long-day plants (those that flower under day-length of less than 14 h, e.g. Irish potato, wheat, barley, oat); short-day plants (those that are included to flower under day-length of less than 10 h., e.g. sweet potato, maize, soybean); and day-neutral plants (those that are not induced by daylength e.g. cowpea).

Light is a climatic factor that is essential in the production of chlorophyll and in photosynthesis, the process by which plants manufacture food in the form of sugar (carbohydrate).

Other plant processes that are enhanced or inhibited by this climatic factor include stomata movement, phototropism, photo morphogenesis, translocation, mineral absorption, and abscission.

However, most tropical crops are highly sensitive to daylength and therefore are identified in two groups:

1. Those with a critical day length of less than or equal to 121/4 h. e.g. Corchorus olitorius; and

2. Those with critical day-length greater than or equal to 121/4 h. e.g. Phaseolus lunatus.

6. Solar Radiation

Surface reflectivity over different agricultural crop surfaces, net radiation (photosynthetically-active radiation, PAR) and energy budget, and the relationship of solar radiation to dry matter production and economic yields, all have implications for agricultural crop production.

Solar radiation is essentially important during photosynthesis, which utilizes visible light to produce dry matter from water and CO2. Thus dry matter production depends on incoming solar radiation and the type of plant that is exploiting it under normal conditions.

Solar radiation is very important in determining the final yield of some crops in areas of adequate water supply e.g. sugar cane and lowland rice.