All fertilizer labels have three bold numbers. The first number is the amount of nitrogen (N), the second number is the amount of phosphate (P2O5) and the third number is the amount of potash (K2O). These three numbers represent the primary nutrients (nitrogen(N) – phosphorus(P) – potassium(K)).

Fertilizers have the following disadvantages:

• They are expensive.
• The ingredients in the fertilizers are toxic to the skin and respiratory system.
• Excessive use of fertilizers damages the plants and reduces soil fertility.
• Leaching occurs and the fertilizers reach the rivers causing eutrophication.

The main disadvantage of inorganic fertilizers is that it costs much higher than the organic fertilizers. This is because in inorganic fertilizers, the nutrients are already in their most basic components, and hence, can be washed away easily, if the plant roots are over watered or watered with force.

Here, the best fertilizers for your garden’s needs.

• Best Overall Fertilizer: Miracle-Gro Water-Soluble All Purpose Plant Food.
• Best for Lawns: Scotts Turf Builder 12.6 lb.
• Best for Tomatoes: Vigoro 3.5 lb.
• Best for Gardens: Jack’s Classic All Purpose Water Soluble Plant Food.

The method of applying fertilizers depends on the nature of your plants, their nutrient needs and the soil.

• Deep Soil Application. Organic manures are sometimes placed on the surface of soil and incorporated into the soil with a plough or rototiller before planting.
• Broadcasting.
• Banding.
• Liquid Application.

Fertilisers supply plants with the elements that may be missing or in short supply in a form that can be used by the plants for faster growth. Most fertilisers supply nitrogen, phosphorus and potassium.

Fertilizers provide crops with nutrients like potassium, phosphorus, and nitrogen, which allow crops to grow bigger, faster, and to produce more food. However, applying excessive amounts of fertilizer leads to the release of harmful greenhouse gases into the atmosphere and the eutrophication of our waterways.

They harm the environment. Lawn fertilizers that can kill weeds have chemicals in them. Usually, all the chemicals do not get absorbed by grass and other plants regardless of how think your lawn is.

Most fertilizers that are commonly used in agriculture contain the three basic plant nutrients: nitrogen, phosphorus, and potassium. Some fertilizers also contain certain “micronutrients,” such as zinc and other metals, that are necessary for plant growth.

Plant fertilizers can poison people and pets if they are inhaled or accidentally ingested. Touching the fertilizer may cause skin irritation, and ingesting it may be poisonous. Nitrates are the ingredients that cause the poisoning. Nitrates are a form of nitrogen that plants can easily absorb.

The two types of fertilizers – inorganic and organic. In the broadest sense all types of fertilizers include any substance, living or inorganic which aids in plant growth and health. We exclude water, CO2, and sunlight.

Excess fertilizer alters the soil by creating too high of a salt concentration, and this can hurt beneficial soil microorganisms. Over- fertilization can lead to sudden plant growth with an insufficient root system to supply adequate water and nutrients to the plant.

The plant will never be able to heal affected foliage and the plant should not waste any further energy on damaged foliage. New foliage will be produced once the plant begins to recover from fertilizer damage.

Plants need to be fertilized because most soil does not provide the essential nutrients required for optimum growth. It took nutrients from the soil to build those plant tissues. By fertilizing your garden, you replenish lost nutrients and ensure that this year’s plants have the food they need to flourish.

Nitrogen is a very important and needed for plant growth. It is found in healthy soils, and give plants the energy to grow, and produce fruit or vegetables. Nitrogen is part of the chlorophyll molecule, which gives plants their green color and is involved in creating food for the plant through photosynthesis.

Why is Nitrogen so important? As the soil fertility page explains, nitrogen is really important for plant growth (structure), plant food processing (metabolism), and the creation of chlorophyll. Without enough nitrogen in the plant, the plant cannot grow taller, or produce enough food (usually yellow).

Nitrogen, phosphorus and potassium, or NPK, are the “Big 3” primary nutrients in commercial fertilizers. Each of these fundamental nutrients plays a key role in plant nutrition. Nitrogen is considered to be the most important nutrient, and plants absorb more nitrogen than any other element.

Organic fertilizers that are high in nitrogen include urea, which is derived from urine, feathers, dried blood and blood meal. Feathers contain 15 percent nitrogen; dried blood contains 12 percent nitrogen; and blood meal contains 12.5 percent nitrogen.

Phosphorus (P) is vital to plant growth and is found in every living plant cell. It is involved in several key plant functions, including energy transfer, photosynthesis, transformation of sugars and starches, nutrient movement within the plant and transfer of genetic characteristics from one generation to the next.

Major organic sources of phosphorus include, again, certain manures, as well as bone meal and pulverized rock phosphate. Rock phosphate is a phosphorus-rich rock that is ground into fine particles that release their phosphorus slowly and over the course of many years.

The most effective methods of adding phosphorous to your soil include:

1. Bone meal – a fast acting source that is made from ground animal bones which is rich in phosphorous.
2. Rock phosphate – a slower acting source where the soil needs to convert the rock phosphate into phosphorous that the plants can use.