Organic Fertilizer as an Alternative to Chemicals

To be able to experience growth in humans, we need a balanced diet which contains all the necessary nutrients. Just as we cannot survive without in our foods, plants can also not survive without the required nutrients and hence the need for fertilizers. Although there are some nutrients in the soil for the plants to feed on, not all can be found in the soil and those that even occur naturally are not in their right proportion and hence the need for an outside source of nutrients called fertilizers.


A fertilizer can be referred to as any soil addition material be it organic or synthetic capable of supplying plants with required nutrients for their growth and development. Fertilizers have been in existence for many centuries now and have been linked to higher and improved crop yield. They are arguably the most important commodities since it is inextricably linked to food security in the world today. Basically, there are two types of fertilizers; organic and inorganic base fertilizers. Organic fertilizers are made up of natural constituents (plant, animal or minerals that occurs naturally) origin. Organism in the soil feeds on the substances by breaking them into nutrients which the plants absorb and use. It must be noted that some of these organic base fertilizers contain substantial quantities of merely one main nutrient but the good news to all lovers of organic base fertilizers is that they also often contain bits of other helpful nutrients.

Inorganic fertilizers are made from synthetic ingredients which are mainly mineral and chemical in nature. They often occur in single or multinutrient forms containing basic, secondary as well as micronutrients necessary for the overall growth and development of the plant. It must be noted that, inorganic fertilizers works mainly on the plants and does not contribute to the maintenance of the soil structure. Our focus here however will be on organic fertilizers. This essay seeks to identify some of the types of organic fertilizers available, its composition, applications methods as well as its advantages and limitations. The importance of organic fertilizers can be understood in four ways:

  • Influence on Soil
  • Influence on plants
  • Environmentally friendliness
  • Health improvement

Organic fertilizer and soil fertility

Organic fertilizers contain energy that are of tremendous benefits to soil organisms. They provide energy and the necessary requirements of minerals for the micro-organisms and soil animals. It is a fact that soil micro-organism lack the photosynthetic ability to capture the suns energy and must survive on the carbon substances the soil has. This is where organic fertilizers come in to provide the energy these micro-organisms depend on. The activities of micro-organisms such as mycorrhizae, fungi, algae and nematodes improves the fertility of the soil and the only known type of fertilizer that provides the conducive environment for these organisms to operate is non-other than organic fertilizers. Bacteria for instance release acids (organic) and this helps the soluble elements in the soil. They release polysaccharides (a complex sugar based compounds) which gives the soil the desired structure through the creation of soil crumps. Actinomyces, a microorganism in the soil also releases antibiotics which are absorb by the roots of plant to defend it against pests. The antibiotic contributes towards the creation of desired ecological balances for soil organisms located on the rhizoplane (root surface) and rhizosphere (soil near the root).

Organic fertilizer also helps improves the water retaining capacity of the soil. Water has been the most important element plants derive from the soil. Organic fertilizers create the desired soil structure which aids the soil to hold water around the root zone and in water filtration as well by functioning as a water sponge. Organic fertilizers contain humic substance that helps the soil to retain water for use by crops/plants during dry seasons or drought. It also helps in the stabilization of the temperature of soil as well as the rate of water evaporation. This is one of the main reasons why organic fertilizers are very important to food security since it can support plant growth even in hostile environment and during extremely dry periods. Organic fertilizers contain humates which helps to degrade toxic materials such as phenols and nicotine in the soil. Humates in the organic fertilizers contain electrically charged substance which attracts and deactivate pesticides and other toxic materials in the soil. Organic fertilizers also neutralize the pH content of the soil and once it has been neutralized, numerous trace of elements which were once in abundance in soil but were inaccessible to the plants becomes available and in very reasonably quantities. Organic fertilizers have also been known to regulate the carbon dioxide in the soil contributing immensely towards the reduction of greenhouse gas emissions. Organic fertilizers are known to reduce leaching into the soil. It has an electrostatic pull which keeps the nutrients from moving beyond the reach of the plant roots and consequently finding its way into water sources which happen more often with the inorganic ones. Organic fertilizers have water bonding property which improves the movement of nutrients from the soil to roots of plants.

Organic fertilizer and plant growth

Research has revealed that plants require six basic nutrients in order to grow. Whiles carbon, hydrogen and oxygen is sourced from air and water, nitrogen, phosphorus and potassium is acquired from the soil and other supplements such as fertilizers. Organic fertilizer is very vital to the growth and development of plants. They provide additional nutrients to help the plant experience better growth and development. One of the most important contributions of organic fertilizers is that, it improves plant metabolism (photosynthesis; the process where plants manufacture their own food using sunlight). It must be noted that plant metabolism itself is the basis of world food. Plants serve as the main source of calories and other important nutrients for mankind and also provide a wide range of other substances that profoundly have direct effects on the human physiology ( human make up including muscles, bones, cells etc). Organic fertilizers therefore play an important role in the ability of plants to improve how they are able to manufacture their own food. Organic fertilizers contain the following nutrients; Nitrogen: Nitrogen is required by plants in very large quantity and helps plant make proteins needed to reproduce new tissues. It is the most important nutrients needed by plants after water. It is essential to plants growth. Phosphorous: Stimulates plant root growth and helps set buds and flowers. Phosphorous also improves the vitality of the plant and increases the size of seeds as well by transferring energy from and within the parts of the plant. Organic fertilizers are known to contain high levels of phosphorous which make the plant develop better.

Potassium: Potassium increases the strength of plants by helping them make carbohydrates. It works as disease resistance and also helps to regulate the rate of metabolic activities. Nevertheless, there are other nutrients such as calcium, magnesium, sulfur as well as other micronutrients - boron, copper among others, which are also present in organic fertilizers that helps in the overall development of the plant. An important tip to know about organic fertilizers is that, they work mostly to improve soil fertility which in turn works on the plant.

Organic fertilizer and the environment

Organic fertilizers are known to have positive effects on the environment leading to environmental sustainability. Organic fertilizers are known to achieve the following in relation to the environment:

  • it does not deplete the soil quality. Organic fertilizers improve the fertility of soil and maintain it for a relatively longer time than the inorganic ones.
  • Organic fertilizers reduce leaching and in the event that some nutrients are washed away into water bodies, the biology of the water does not undergo any significant changes.
  • Organic fertilizers have been known to reduce pollution and do not contribute towards global warming, researchers have indicated.

Organic fertilizer and health

Farmers who apply organic fertilizers produce the cleanest and safest food, as compared to those who use inorganic fertilizers since the constituents in the organic fertilizers are not harmful to humans. However, protective clothing must be worn during the application of the fertilizers. Organic fertilizer usage ensures that food produced for the consumer does not have any negative effects on their health.

Limitations of organic fertilizers

Although organic fertilizers have numerous advantages on the soil, plant, the environment and the health of both farmers and consumers, it has its limitations. These include:

  • The Release time

Since the nutrients in organic fertilizers has to be broken down before they can be absorbed by plants, it usually takes a much longer time for it to start working at full capacity. The release is also dependent on the kind of temperatures and microorganisms present in the soil. Very cold temperatures and damaged soils may take longer in breaking down the fertilizer before the plant can use them. One other limitation of organic fertilizer is that, it might contain more of one nutrient than the others making it an unbalanced nutrient.

  • Bulky, difficult to transport and unavailable in large quantities

Organic fertilizer can be very bulky making it very difficult to move around. It may be unavailable for use on very large commercial farms since most production of the fertilizer is done on a small scale usually by farmers who end up using it themselves. It is labor intensive as well especially turning compost and spreading them on the farm.

  • Looks simple but very inconvenient

Preparing compost looks easy but can become very inconvenient especially with the smell. Incomplete ones may also contain pathogens which can enter water systems or the crops which could be harmful to humans. Organic fertilizers stimulate the growth of bacteria and their use increases the amount of oxygen demand. Applying too much of it can result in depletion of oxygen in the soil and an increased in bacterial activity in the soil can also increases the pH of the soil.

Types of organic fertilizers

There are three types of organic fertilizers;

  • Plant based organic fertilizers
  • Animal based organic fertilizers and
  • Mineral based organic fertilizers

Plant based organic fertilizer

Plant based organic fertilizers have their origins in plant materials as it name suggests. They usually have between small to reasonable amount of Nitrogen, Potassium and Calcium (N-P-K) levels but then the nutrients from plant based organic fertilizers are quickly converted and becomes accessible to the plants. Research has shown that some of these fertilizers even provide additional traces of micronutrients as well as other minerals needed for plant growth. Types of plant based organic fertilizers include:

Alfalfa meal

Alfalfa meal is mainly used to improve the organic matter found in the soil structure. Nutrients such as nitrogen, potassium and other traces of minerals can also be found in them. Another important constituent found in alfalfa meal is Trianconatol, a natural fatty alcohol growth stimulant. It is produced using fermented alfalfa plants. Alfalfa meal is derived from alfalfa plants and shredded into pellet form. It is free from weed which makes it a good fertilizer. It improves the fertility of the soil and helps the plant to grow as well. Adding a cup of alfalfa meal twice month to worm bins will improve their activity and for every 11 square yard (100 square foot) of vegetable garden.


Compost adds organic matter to the soil structure.Composting itself is a natural process of recycling decayed organic matter into rich soil. The colour/color of finished compost is soil darkish brown, powdery and has an odour/odor like that of a forest floor. Basically there are three types of composting:

  • Grass recycling: Where grass clippings are left to decompose
  • Backyard composting: Where leaves or straws and food scraps or anything green are put together to decompose
  • Worm composting: Where worms are made to feed and break down food scraps

Compost can be applied in the following ways;

  • As a mulch: Spread the compost around the plants to cover about 2 to 3 inches of the surface once or twice a year.
  • As a soil amendment: Dig down between 2 to 4 inches deep and deposit the compost there and mix it up with the soil.
  • As a compost tea: Compost tea is a liquid matter that comes from the compost itself. Sometimes, the tea comes naturally, but one can produce the tea by soaking the compost in a gallon for some days. Simply pour the tea on the plant when it is ready.

Compost comes with the following limitations as well;

  • Considerable space is needed to prepare compost
  • A lot of time is also needed.

Nevertheless, using compost as an organic fertilizer is extremely beneficial to both the soil and the plant.

Corn Gluten Meal

Corn gluten meal is a powdery byproduct of corn milling process. It offers a non-toxic and effective way to nourish the soil and the plant and can be used to suppress weed as well. It contains nitrogen, potassium and calcium in reasonably quantities. It comes in three forms:

  • Unprocessed: It is in a powdery state and can be spread using the hand.
  • Granulated: Can be mixed with water and made into a paste
  • Pelletized: It can also be broadcasted using the hand

Cottonseed meal

It is a natural fertilizer that is from cotton seed. It is 100% pure with no added materials and is chemical free. It’s a slow-release fertilizer and contains nitrogen, phosphorous and potash. Cottonseed meals improve the soil texture and conserve the moisture in the soil as well.

Kelp and seaweed

It is from sea plants and although it contains small amounts of nitrogen, potassium and calcium, it has important micronutrient, growth stimulants, vitamins and minerals that help plant grow and increase their yield.

Soybean meal

Soybean meal has very high nitrogen content and a good source of phosphorous as well. ===Animal based organic fertilizer

Animals also produce organic fertilizers that can be used by plants and improves the fertility of the soil as well. Types of animal based organic fertilizers include:


Manures provide organic matter to the soil content, nonetheless most contain small nutrient value. Although some do have a significant amount of nitrogen, they can best be used as part of compost since fresh manure has the potential of burning the roots of tender plants.

Bat/seabird guano

The fecal matter from bats and seabirds can be used as fertilizers. It is in a powered or pellet form and has high levels of nitrogen in them. Bat guano only has some amount of phosphorous but no potassium whiles the seabird guano contains both phosphorus and potassium is a minute volume. The nitrogen can burn plants if it is not used carefully and they tend to be quite expensive than manures from land animal.

Blood meal

Blood mean is a powdered blood from animals that have been slaughtered. Its main nutrient is nitrogen and contains other important micronutrients as well. It is said that leafy plants that depends much on nitrogen like the lettuce develop well when the blood meal fertilizer is applied.

Bone meal

Bone meal is sourced from fish or animal bones and it is usually in a powdered form. It has nitrogen as its main nutrients and also contains other micronutrients as well.

Fish products

Fish by-products are very good source of fertilizing farms and gardens and they come in different forms. Fish emulsion, is a liquid base fertilizer and is sourced from fermented remains of fish. It has the three main nutrients, nitrogen, potassium and calcium in very reasonable quantities and also adds trace of mineral elements to the soil to improve its fertility. It works better on young plants and helps them to develop well. Hydrolyzed fish powder also has higher nitrogen levels and it applied by mixing with water and spraying on the plants. Fish meal also is high in nitrogen and phosphorus levels and is applied directly to the soil to improve its fertility.

Mineral-based fertilizers

Rocks undergo weathering to disintegrate into soil and release its minerals content as the weathering occurs. It takes a very long time for the nutrients in the mineral to fully function in the soil. Some of mineral based fertilizers include:

Chilean nitrate of soda

It is from Chile, highly soluble and acts fast. It contains nitrogen in a very high quantity. It contains sodium as well so it is not advisable to be applied on arid soil.

Epsom salt

It contains magnesium and sulfur and it is applied by mixing with water and spraying directly on the leaves of the plant. It works very well on tomatoes, pepper and lettuce and gives great results over time.


Greensand contains potassium and other micronutrients needed for the growth and development of plants. It comes in powdered from and takes some time before it breaks down completely to release its rich potassium nutrients. Adding greensand to your plants will help it grow well.


Gypsum also comes in a powdered form and contains calcium and sulfur as its main nutrients that it adds to the soil structure. It adds calcium in high quantities to the soil without increasing the pH of the soil.

Hard-rock phosphate

Hard-rock phosphate contains phosphorous and calcium which when added to the soil can improve the fertility of the soil but can also raise the pH of the soil. This fertilizer should not be used when the soil is already alkaline. It takes a long time for the nutrients to build up.

Soft-rock phosphate

It’s also called colloidal phosphate and contains phosphorus and more calcium than hard-rock phosphate. The soft-rock phosphate comes in powder form and breaks down slowly and also contains many other micronutrients.


It is high in calcium and magnesium and comes in a powdered form. One needs to know the pH of the soil before applying limestone as a fertilizer to the soil.

In Conclusion

Using organic fertilizer indeed comes with its own challenges but it is a fact that the advantages far outweigh the disadvantages ranging from the economic, social, environmental and health wise.


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