Have you ever seen a fertilizer bag with NPK written on it? What is it? First, let’s understand the basics – the letters (NPK) you will find on a fertilizer bag stand for Nitrogen, Phosphorus, and Potassium. These are the three primary nutrients plants need to grow. The number on the label indicates the ratio of the three ingredients in the container. Many manufacturers, like Buoyancy, include these ratios to ensure you know about what you are investing in. Even if you do not see the letters, you will find three numbers which say – 5-10-5. This helps you easily understand the percentage of nitrogen, phosphorus, and potassium, which is 5% nitrogen, 10% phosphorus, and 5% potassium. A fertilizer bag contains only 20% of these nutrients, and the remaining 80% is filler or minor nutrients. Plants need 16 nutrients in total, which they get from air, water, and soil. 

Types of NPK Fertilizers

Here are three types of NPK fertilizers –

Balanced Fertilizers

A fertilizer is considered a balanced or complete fertilizer because its nitrogen, phosphorus, and potassium proportions are equal, which is listed as 10-10-10. 

Incomplete Fertilizers

A fertilizer is considered incomplete if any one of the ratios is zero. For example, if a fertilizer has a ratio of 10-0-10, it is considered incomplete. However, an incomplete fertilizer cannot always be considered inferior to the complete one. This is because your soil might already have an excess of one of the three nutrients. Hence, adding more would lead to poor soil quality, which ultimately will harm your plants. So, it is advisable to check the soil quality before making any decision. 

Organic Fertilizers

Organic fertilizers are the ones which provide nutrients from plants, animals, or minerals. You must always look for the ‘Organic Fertilizers’ labeled on the package, which comes with a percentage to showcase if it is synthetic or natural. For example, if the label says 20% nitrogen, this means – 6% synthetic and 14% organic. Organic fertilizers usually include – manure, kelp, blood and bone meal, fish emulsion, alfalfa meal, cottonseed, soft rock phosphate, green sand, and sewage sludge. 

What Are the Uses of NPK Fertilizers?

Here are the uses of each nutrient in the NPK fertilizers –

Nitrogen

Nitrogen plays a key role in the plants coloring and making chlorophyll – which makes it an important factor for leaf development. Fertilizers that have high nitrogen content are used mainly on grass and other plants where greenery is more important than flowering, such as succulent plants, corn, broccoli, etc. So, if you see a yellowish color on your plant, feed them nitrogen. 

Phosphorus

This is the middle number in the NPK series, which refers to the percentage of phosphorus in the fertilizers. It helps in the growth of the roots, fruiting, and blooming. Mainly, plants that bore fruits or flowers require phosphorus, as it contributes to rooting and seeding formation. 

Potassium

Potassium is the last ingredient in the NPK fertilizer, which contributes to the overall health and vigor of plants. It helps strengthen the plant, thus protecting it from any plant diseases, in addition to aiding in the water and nutrient movement in the plant. 

Fillers/Other Nutrients

Many fertilizers include other nutrients such as calcium, magnesium, iron, and some percentage of micronutrients.  NPK fertilizer manufacturers, such as Buoyancy, include their percentage of the nutrients. This helps you buy the product that suits your needs. It is always advisable to use fertilizers in the right way so that it does not hurt your plant. Thus, always check your soil and the area around them to ensure their safety.