ORGANIC FERTILIZERS: ADVANTAGES AND DISADVANTAGES

Fertilizers are generally of two types: Organic and Inorganic.

 Organic Fertilizers

Organic fertilizers are also known as natural fertilizers or manures. They are derived from animal waste and plant materials. Organic fertilizers can be derived from several sources on the farm.

1. Animal manure

Animal manure, also known as pen manure, is derived from partially decomposed solid materials produced in livestock pens. These manures are composed of animal droppings or dung, litter, bedding, and slurry from washing the pens of farm animals such as dairy cattle, goats, and sheep.

2. Composting

Composted manure is a type of organic fertilizer made from plant materials like leaf litter, grass clippings, and crop residues. In the composting process, these plant materials are allowed to decompose with the help of microorganisms.

3. Green manure

Green manure is a type of manure that is derived from using a green crop which is usually a legume crop. The crop is ploughed and incorporated into the soil.

4. Bonemeal 

Bonemeal is made by grinding bones from meat-processing companies. It contains 

some nitrogen but has large amounts of phosphate. 

Advantages of Organic Fertilizers

Organic fertilizers offer several benefits: 

 

Encourages recycling

Waste material can be converted into valuable fertilizer, helping to minimize waste disposal.

 

Improves soil structure

The physical appearance of soil is known as soil structure, and it refers to how individual particles are packed together to form clusters or aggregates. Having a good soil structure is essential for root development and the uptake of nutrients by plants.

Adding organic fertilizers to the soil can improve its structure in several ways. It can reduce compaction and loosen clay aggregates, making it easier for plant roots to penetrate the soil. Additionally, organic fertilizers can bind sandy soil particles together into aggregates, creating a more porous and stable soil structure. This, in turn, improves soil health and promotes better root growth for plants.

Improves drainage

It is crucial to have good drainage for several reasons. Firstly, it prevents the soil from becoming waterlogged and enhances its structure. This, in turn, improves crop yields as it ensures that crops have the right balance of air and water in the soil and prevents the leaching of essential nutrients. Organic fertilizers are crucial in improving soil structure, making it crumbly, and allowing water to penetrate the soil more easily. This helps prevent waterlogging and promotes better root growth in plants. Additionally, by increasing water filtration and reducing runoff, water is better able to reach the roots of plants.

Improves water-holding capacity

When organic fertilizers are added to the soil, they can improve its water-holding capacity by increasing its ability to retain water, which is essential for plants, especially during dry seasons.

Improves aeration

The addition of organic fertilizers to the soil enhances soil aeration by creating air spaces in the soil which is essential for providing oxygen to plant roots and beneficial soil organisms. 

Environmentally friendly

Organic fertilizers are considered to be environmentally friendly for several reasons. They are renewable and sustainable since they come from natural materials such as animal manure and compost. They encourage microbial activity in the soil and promote biodiversity. Organic fertilizers release nutrients slowly, which can reduce the risk of over-fertilization of plants. They prevent contamination and pollution of water sources and reduce the risk of harming beneficial organisms.

Supplies nutrients at a steady rate for a long time

Organic fertilizers decompose slowly, gradually releasing nutrients and can therefore provide plants with a consistent, prolonged supply of essential nutrients.

 

Saves money

Organic fertilizers and organic amendments can often be less expensive than synthetic fertilizers and may help save money in the long run by improving the soil's health and fertility.

Disadvantages of Organic Fertilizers

Nutrient content

The main macronutrients required by plants are nitrogen (N), phosphorus (P), and potassium (K). Determining the nutrient content of organic fertilizers can be challenging because it depends on the materials from which they are made. For instance, some organic materials, such as chicken manure, have a very high nitrogen content and can burn plants if not allowed to decompose sufficiently. To create a more balanced organic fertilizer, consider using blended organic fertilizer derived from a mixture of plant and animal materials.

Time to decompose

Organic fertilizers must first decompose before their nutrients become available to plants. This process is rather slow because the materials need to be broken down by microorganisms. Typically, it takes about 2-6 weeks for the decomposition process, depending on the organic material. Some materials, like chicken litter, may take much longer to decompose (around 90 days) due to their high nitrogen content. Applying them to plants too early can cause burns.

Storage

When using organic fertilizers, it's important to have sufficient storage space as they tend to be bulky and messy. If you are considering making your own organic fertilizer, it should be stored far away from houses due to potential odour, the presence of microorganisms, and the attraction of flies during the decomposition process.