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Mixing Fertilizer in Soil: The Pros and Cons Explained

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The fertility of soil can be increased by adding fertilizer to it and there are some advantages in incorporating the fertilizer within the surface.

There are two types of fertilizers that can be used in soil:

  1. Organic fertilizers
  2. Inorganic fertilizers.

Fertilizers can be mixed 2 to 3 Inches into the soil to quickly provide plants with nutrients. Mixing fertilizers into the soil helps prevent them from being washed away by rain or being affected by direct sunlight. Organic fertilizers are more beneficial than inorganic fertilizers when mixed into the soil because they can prevent root burn.

Organic fertilizer releases nutrients more slowly into soil preventing loss through leaching as well as preventing root burns by direct contact.

We will look at mixing fertilizer in the soil and its effectiveness in increasing soil fertility, and the advantages and disadvantages of doing so.

The Benefits of Mixing Fertilizers in Soil

Mixing Fertilizer in Soil

The following are the advantages of Mixing fertilizer in the soil.

1.    It increases crop yields due to early access to nutrients in the soil.

2.    It helps the crops grow faster, mainly when hybrid seeds are used.

3.    It quickly improves the soil texture, recycles nitrogen, and introduces essential bacteria in the soil.

4.    It helps in applying a specific nutrient that might be lacking or insufficient in the soil.

5.   It will be easier for the crops to absorb the nutrients directly from the soil.

The results would be the same if this method were applied to raised rows, flat rows, or potted plants.

I have had the best results when growing healthy plants by using this Miracle-Gro fertilizer on indoor and garden plants. It’s excellent value for money and will last a long time.

Miracle Grow Soluble Fertilizer

Disadvantages of Mixing Fertilizers in Soil

As we have seen above, there are benefits to using fertilizers. However, there are also disadvantages to mixing fertilizers in the soil. The following are the disadvantages.

1.    Fertilizers help crops grow faster; weeds also get a boost when fertilizer is added to the soil. As a result, you might incur extra costs of weeding the garden.

2.    When fertilizers, especially artificial ones, when mixed,  the soil structure may not improve the soil structure.

3.    Excessively used fertilizers damage the roots by causing burns and reduce soil fertility.

4.    When you use fertilizers for long periods, they can reduce microbial activity and disrupt the pH of the soil.

5.    When leaching occurs and drains to the nearby rivers, they cause eutrophication.

Increases the potency of the fertilizerYoung plants may not be able to access the nutrients it provides if mixed too deeply
Promotes faster plant growthIncreases the potential for leaching of nitrogen into waterways
Reduces the availability of fertilizer for weedsRequires more time and effort in mixing the fertilizer within the soil
Promotes rapid nitrification of ammonium compoundsGenerally requires more fertilizer
Retain nutrients during rapid soil erosion
Requires less fertilizer per acre
Reduces the nullifying effects of sunlight on fertilizer.

How do you Add Fertilizers to the Soil?

If you want to add fertilizer to your soil, there are four ways you can do it;

1. Broadcasting before planting – 

Using this method, you can spread the fertilizer particles evenly over the garden soil and mix it to a depth of around 2-3 inches before you start making the rows. This method is the best for home gardening and is less likely to harm the plants.

2. Side dressing – 

This is a type of fertilizer application. It is mostly used in sandy soil where the fertilizer is sprinkled along the sides of the plant rows. 

3. Banding – 

Here, you apply the fertilizer along a strip, 2 inches deeper and 2 inches to the side of the row before you start planting.

4. Liquid application – 

This is applying fertilizer in its liquid form. It is applied by spraying cans or applied with sprinklers or furrow irrigation. 

This type of fertilizer is sprayed on the leaves when they show signs of nutrient deficiencies. 

However, you should be pretty careful when spreading since if the solution is too strong, it can scorch the plant leaves.

A more efficient way of adding fertilizers if you are planting in containers is by bottom watering.

Will Mixing Fertilizer in Soil Make Plants Grow Faster?

green and white prills with yellow balls in soil

Mixing fertilizer into the soil helps the plants gain more nutrients like potassium, nitrogen, and phosphorus at a faster rate and quickly boosts plant growth within a shorter time period.

Here are the macronutrients (NPK) and their benefits – 

Nitrogen (N) –

Nitrogen also helps the plant produce parts of a plant like flowers, stems, and fruits. In addition, it helps in the quality of appearance of foliage and makes it grow faster generally.

Phosphorus (P) –

Phosphorus is beneficial to the roots. It helps in the production of organic compounds like starches and oils, which are responsible for the growth of the rooting system.

Phosphorus also helps produce chlorophyll, a green pigment responsible for absorbing light to provide energy for photosynthesis.

Potassium (K) –

Potassium helps in building proteins, fighting unhealthy states, and is used in the process of photosynthesis.

As a result of all the above elements, fertilizer acts as a catalyst to a plant’s growth rate. 

Plants can grow and do reasonably well even without fertilizer. But when you apply fertilizer, they will tend to grow faster than when planted without fertilizer.

Can Sunlight Affect Fertilizer?

Sunlight can affect applied fertilizer. Therefore, it is recommended that you apply fertilizer when the temperatures are cool with little sunlight and less wind. 

Mixing fertilizer within the soil will prevent sunlight from coming into direct contact with it. This significantly reduced the nullifying effects sunlight has on the fertilizer. 

As a result, the fertilizer can be more potent when providing nutrients to the soil.

Application of fertilizer is recommended to be done during early mornings or late evenings.

When you are applying the fertilizer in the evening, you will need to do it via fertigation, which will allow you to inject it into the flowing water to reach the roots without wetting the leaves.

This process makes sure that the leaves are not dampened overnight, and the plant acquires the proper fertilizer for favorable growth of the plant.

Types of Fertilizer you can Mix into Soil

Organic Fertilizer

Organic fertilizers are great for mixing into the soil; they mainly include manure, peat, guano, slurry, worm casting, and seaweed. 

These are also known as natural organic fertilizers.

On the other hand, there are artificial organic fertilizers, compost, blood meal, seaweed extracts, and bone meal. 

All these are organic fertilizers and can be mixed in with the soil before you start planting.

Additionally, you can also mix old mulch or dead leaves into soil which adds an organic source of slow-release fertilizer to the soil.

Inorganic Fertilizer

Most of the minerals in inorganic fertilizer are mined from the earth, and balanced inorganic fertilizers are high in all three macronutrients and can contain ammonium sulfate, magnesium sulfate, and potassium chloride.

Some Examples of Inorganic Fertilizers:

  • Ammonium Nitrate
  • Ammonium Sulfate
  • Potassium Chloride
  • Triple Superphosphate

If you want a slow-release fertilizer that will ensure your plant grows healthy for a long time with minimal intervention, I recommend Osmocote Smart-Release Plant Food.

Osmocoat fertilizer

Slow-release fertilizer can be placed on top of soil and also mixed in with the soil.

The downside of having the fertilizer on top of the soil is that when it rains, or the plant is watered, the water washes off the coating in a short period of time causing the fertilizer to be released into the soil, which reduces the longevity of the fertilizer.

However, if the slow-release fertilizer is mixed into the soil, the soil acts as a protective barrier from rapid water washing from watering or rain. This results in the fertilizer lasting for a longer period of time within the soil.

As a result, the nutrients are released slowly as intended.

Advantages of using organic fertilizer

Soil Minerals
  • Organic fertilizers work slowly. It takes some time for the soil to break down the fertilizer. This is an advantage to the plants.

    They will gradually be supplied with fertilizer over a period of time as the fertilizer slowly releases its nutrients to the soil.
  • They are easy to apply.
  • They are safer than any other type of fertilizer for you, your plants, and any other soil microorganisms.
  • They improve the soil’s water holding capacity. Organic materials improve soil texture, which allows it to retain moisture much longer.

Table Showing the Minerals and Nutrients in Fertilizer

NutrientUse Deficiency Symptom
Nitrogen – NA major component of chlorophyll and is used in photosynthesisStunted Growth, Pale color, Light green yellowish leaves
Prosperous – PEnergy transfer, photosynthesis, the transformation of sugars and starchesStunted growth, darkening of the leaves
Potassium – KEnzyme activation in plants, Increases root growth and improves drought resistance. Brown scorching and curling of leaf tips
Calcium – CaTo provide structural support to cell wallsPlant dark green, Drying starts from the tips, Tender leaves pale
Magnesium – MgUsed in chlorophyll production and enzyme regulationPaleness from leaf edges. Edges have cup shapes folds
Sulfur – SUsed in the formation of amino acids, proteins, and oilsLeaves light green, veins pale green
Boron – BUsed for cell wall formation and plant stabilitydiscoloration of leaf buds. breaking and dropping of buds
Copper – CuPhotosynthetic and respiratory electron transport chainsPale pink between the veins. wilt and Drop.
Chlorine – ClOsmotic and stomatal regulation, disease resistance and toleranceWilting of leaves, especially at the margins
Iron – FeUsed for the synthesis of chlorophyll, and it is essential for chloroplast functionLeaves are pale, No spots, major veins Green
Manganese – MnSustains metabolic roles within different plant cell compartmentsLeaves pale in color, veins dark green
Zinc – ZnFormation of chlorophyll and some carbohydratesLeaves pale, dark spots on leaf edges
* These are the more predominant nutrients found in fertilizers and can vary by brand.

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