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The Ultimate Guide to Compound Fertilizer

Explore the benefits of compound fertilizers for optimal plant growth, including types, application methods, and their impact on soil and crops.

Fertilizers ensure healthy growth of the plant’s roots, leaves, flowers, and fruits. These may come in various compositions and forms, such as granules, powder, or liquid. Fertilizers are formulated with minerals such as nitrogen and potassium to prevent root decay or leaves becoming yellow. Using the right fertilizers ensures all the nutrients are readily available to the plants for growth.

Depending on the growth of the plant, you may use straight or compound fertilizers. Straight fertilizers come with a single ingredient and are useful if one nutrient is missing from the soil. On the other hand, compound fertilizers contain more than two constituents. 

One common type of compound fertilizer is Nitrogen, Phosphorus, and Potassium fertilizer. NPK fertilizers are mostly used for vegetables, sunflowers, corn, and wheat. This composition makes them fit for adding multiple nutrients into the soil. We’ll discuss compound fertilizers and their types in more detail. 

What are Compound Fertilizers?

What are compound fertilizers

As mentioned above, compound fertilizers contain more than two or three ingredients. The most common one is the NPK fertilizer. It is available in different percentages of nitrogen, phosphorus, and potassium.

These may come in granules and powder forms. Forming compound fertilizers makes sure the soil does not lack single nutrients, and the plants can grow with the right nutrients. Note that compound fertilizers are different from blended fertilizers. 

These fertilizers may be made using bulk blending methods to ensure each granule has the same composition with a homogenous mixture. Therefore, the application will be easier and uniform. For instance, NPK fertilizers use nitro-phosphate processes with chemical granulation. 

During the process. Talking about blended fertilizers are heterogeneous, and granules will be of different compositions. 

Types of Compound Fertilizers

Types of Compound Fertilizers1

Here are the common types of compound fertilizers.

Synthetic Compound Fertilizers

Synthetic compound fertilizers have concentrated nutrients. They are used when the plants need the most nutrients during the flowering or blooming stage. Synthetic compound fertilizers are strong as they are heavily concentrated; hence, they should only be used in small quantities. 

Slow Release Compound Fertilizers

Slow-release fertilizers are good for adding nutrients at a consistent rate. This may be added over weeks or months, fulfilling the needs of a growing plant. These fertilizers come with a special coating to release the nutrients slowly into the soil. 

They are ideal if the soil composition is good and only needs a little boost at intervals. The consistent supply of nutrients ensures that plants and trees are able to grow properly without the risk of over-fertilization. 

Water-Soluble Compound Fertilizers

As the name says, these are soluble in water and can be added to the soil by quickly mixing into the water. They can also be added to the irrigation system to drip the fertilizer slowly into the soil. These fertilizers come in high concentrations to make up for the high runoff rate with the groundwater. Water-soluble fertilizers are good for quickly adding the nutrients to the soil. 



These are made using living microorganisms. Bacteria and fungi may be used to add nitrogen to the air. These fertilizers help in fixing the soil composition naturally without adding any chemical granules.

Organic Fertilizers 

Organic fertilizers may be made with organic constituents such as manure or fish meal. These blends are not that strong; hence, they have to be applied more frequently. They are ideal if your plants require less fertilizers. 

Fertilizer Type 


Synthetic Compound Fertilizers


Slow Release Compound Fertilizers

sulfur-coated urea and polymer-coated fertilizers.

Water-Soluble Compound Fertilizers

Ammonium nitrate, calcium nitrate, and potassium chloride


Rhizobia bacteria and mycorrhizal fungi

Organic Fertilizers

Compost, bone meal and manure

How are Compound Fertilizers Different From Straight Fertilizers?

Straight fertilizers will offer just one type of nutrient. If, after soil testing, the soil lacks one particular nutrient, straight fertilizer is the right choice. Compound fertilizers are for soils that lack more than two or three nutrients. 

The NPK compound fertilizers may come in a 20-10-10 or 10-8-20 ratio. The first number will depict the percentage of nitrogen, the second will be for phosphorus, and the third will be for potassium. 

Choosing compound fertilizers offers the soil the right balance of nutrients. It is often better than straight fertilizers. Always conduct a soil test to ensure the right choice of fertilizers. Consider the type of plants and their growing stage to choose fertilizer types and composition. 

Compound Fertilizers to Choose From

Here are some common compound fertilizers: 

Ammonium sulfate

It is rich in nitrogen and sulfur, which is good for making the soil acidic for the plants. Usually added to enrich the plant’s growth, ammonium sulfate also acts as a herbicide. It mixes well in water and is suitable for extra dry soils. 

Nitrogen, phosphorus, and potassium (NPK) fertilizers

NPK fertilizer is a broad-spectrum fertilizer for the overall growth of the plant. The nutrient profile of these fertilizers will be mentioned on the pack in ratios such as 10-10-20, indicating the percentage of nitrogen, phosphorus, and potassium. 

Due to its less solubility in groundwater, it is ideal for dry soil. Moreover, it retains the fertilizer for longer in the soil. With the right use of this fertilizer, the plants will give a good yield and will not wilt in the growing stage. Food crops such as corn and wheat benefit from NPK fertilizers, giving more grains after use.

Potassium chloride 

Potassium-rich fertilizer is used for plant growth and crop yield. Potassium helps plants derive more water and oxygen from the soil and atmosphere. By releasing carbon dioxide, potassium chloride also helps in osmoregulation and photosynthesis to ensure good plant health. 

Another benefit of using macronutrient potassium chloride is that it deters pests from attacking the crops. Water vapor, oxygen, and carbon dioxide.

Triple superphosphate

This is used in the growth stage of the plants as it promotes root development. A good root system allows the plants to take in more nutrients to support their growth. 

Calcium nitrate 

Containing nitrogen and calcium, this fertilizer is used for plant and fruit growth. Calcium nitrate fertilizer can help in improving the root health of the plants. This lets the plant absorb more nutrients, leading to better crops in terms of taste, nutrition, and shelf life. 


Another good fertilizer to promote plant yield and bloom growth. The leaves will appear lush when urea is used as the fertilizer. Urea can be added to the cultivation of plants like cereals, vegetables, oilseeds, and fruits.

The Manufacturing Process

The Manufacturing Process1

Most compound fertilizers are made using urea, sulfur, potassium, ammonia, and ammonium phosphate. These constituents decide the method of production to ensure the correct nutrition content. 

Here is the production process of compound fertilizer: 

  • Pipe-cross reactor: This method is used for making ammonia-rich fertilizer. The pipe-cross reactor melts ammonia(NH3), potassium and phosphorus. These ingredients are then made into a solid mix. 
  • Compaction: Fertilizer ingredients are compacted together to form a homogeneous bonded mixture. This method allows the combination of multiple compound fertilizer ingredients by forming a chemical bond during compaction. 
  • Accretion: A nutrient-rich liquid is carefully layered on top of granules. This layer is allowed to harden and dry before adding more on top. The process is repeated until the desired nutrient profile is available. 
  • Nitrophosphate process: This method is used to make nitrogen, phosphorus, and potassium fertilizer. Phosphate rock is added to nitric acid to create a reaction. This results in a solid fertilizer. 

Benefits of Using Compound Fertilizers 

Here are some benefits of using compound fertilizers for plants: 

  • Compound fertilizers make farming easier by supplying more nutrients with a single application solution. 
  • The value of ingredients can be adjusted to get the right amount for the soil structure and plant needs. 
  • Compound fertilizers have balanced amounts of nutrients, so the soil quality can be improved quickly. 
  • Farmers can choose custom compound fertilizer blends to suit the crops and soil needs after testing. 
  • These fertilizers prove to be more affordable than the dependency on separate fertilizers. 
  • There will be a significant improvement in plant health and crop yield after using compound fertilizers. 
  • Many compound fertilizers maintain the soil and plant health, thus reducing the need to add pesticides. The impact of this move is reduced soil and groundwater pollution. 

Are There Any Drawbacks of Compound Fertilizers?

Are There Any Drawbacks of Compound Fertilizers

A word of caution when using these fertilizers is to never overdo it. Over-fertilization may cause the soil to change abruptly. As a result of this, the plants will develop unhealthy roots and leaves or little yield. 

For instance, adding too much nitrogen may leech into the groundwater. If you add too much NPK fertilizer, it may kill microorganisms that are essential for plant health. So, the best way to use fertilizers is to add them only after conducting a professional soil test. 

Wrapping Up

Now you know all about compound fertilizers and how essential they are in plant growth. Compound fertilizer contains necessary constituents like potassium, phosphorus, nitrogen, and sulfur. They help in ensuring healthy roots, leaves, flowers, and fruits. 

Compound fertilizers are great for soils that are lacking in moisture and nutrients. They can improve water retention in soil, which is ideal for maintaining root health. Apart from the right soil and plant care, fertilizers in the right quantity prove to be a great farming and gardening tool. You may also contact us to learn more about compound fertilizers.

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