Everyone wants the perfect garden! However, there is no one-size-fits-all solution to plant nutrition.

How do the different types of fertilizers used in agriculture impact and power growers and their resources? What are the ways of application, the main benefits, and the most revered examples of highly potent nutrients? Finally, which plant feed products can you use to enhance your garden?

Let us explain all this and more, step by step.

Organic vs. Inorganic Fertilizers: Understanding the Difference

One trip to your local garden center, and you’ll find tons of different products on the shelves. However, they all fall into two main categories: inorganic, or chemical, fertilizers and organic fertilizers.

Here’s what you need to know about both of them:

Inorganic fertilizers

Inorganic types are made from chemical compounds during a complicated industrial process. The biggest fertilizer companies mine mineral rocks or gases, which are then converted into plant food. The source materials are usually oxidized or treated with acids before they can end up packaged and ready to go into our gardens.

You’ll see them in all horticulture stores in bags, boxes, or bottles in granular, powder, or liquid forms.

The great thing about synthetic fertilizers is that they can have all three primary macronutrients—nitrogen (N), phosphorus (P), and potassium (K), or just one of them. And it’s all crafted in specific proportions, so you know exactly what you’re getting with your chosen NPK fertilizer.

However, there are downsides to all the perks. What makes artificial products problematic is their harmful impact on the environment. Leeching, erosion, and water pollution are just a few of their damaging side effects. Yes, your plants will grow strong, but you have to be cautious of the negative side effects in your garden.

 

Organic fertilizers

Just like chemical products, organic fertilizers contain nitrogen as well as phosphorus and potassium, but usually in a much less concentrated form. Natural fertilizers are typically made from materials such as livestock droppings, food waste, bone and blood meal, gypsum (calcium carbonate), algae, mineral rocks, and more.

As you can tell, most of these are byproducts of the food manufacturing process and cattle farming. Essentially, organic fertilizers are recycled, so no value is wasted in the whole production chain.

There is one major caveat, though. Since they are not artificially made in a lab, you can’t control the exact nutrient ratio or potency that’s optimal for your soil and plants. That’s why you often need to apply more quantity for the product to be effective.

So, what’s the best organic fertilizer type to use? There is no single product that does it all, but you’ve got plenty of options to choose from. Plus, you can make your own fertilizer at home. There are two popular methods that are affordable, and pretty much everyone can do them:

  • Compost is rightfully dubbed as “black gold,” the king of organic fertilizers. This nutrient-rich substance is packed with everything your garden needs and loves. It’s better for the environment too—after all, it’s no longer “waste” if our kitchen scraps can be turned into a superfood for plants.
  • Manure is another type of fertilizer made of agricultural waste. In this case, droppings from cows, chickens, and other factory-farmed animals are the primary sources of manure. It’s a natural source of NPK and acts as a biostimulant that increases soil carbon content.

Below, you’ll find a simple comparison table that should give you a basic overview of the main differences between the two fertilizer types:

Characteristics Organic Fertilizers Inorganic (Chemical) Fertilizers
Source Derived from natural materials such as compost, manure, bone meal, etc. Typically synthesized from minerals or synthetic chemical compounds
Nutrient content Can’t be controlled during production Contains specific elements in concentrated forms in precise ratios
Nutrient absorption Nutrients are released slowly and absorbed gradually by plants. Nutrients are quickly available for uptake.
Impact on soil Improves soil structure, fertility, and microbial diversity Can degrade soil quality over time due to chemical buildup
Environmental impact Generally considered more environmentally friendly Causes soil, water, and air pollution if overused or mismanaged
Cost Often more expensive initially due to production methods Cheaper because of the higher nutrient concentration

Different Fertilizer Types and Their Pros and Cons

Alright, we’ve set the stage with the two primary types of fertilizers. Now, let’s break them down into some of the most widely used products.

Granular fertilizers

As the name suggests, granular fertilizers come in solid form. They are typically used as a pre-seed top dressing that quickly dissolves and delivers plant nutrients to young crops. All you have to do is scatter the product on top of the soil in a row or around individual plants. This makes them super handy for taking care of your lawn, growing veggies in your garden, or even large-scale farming. Just make sure you thoroughly moisten the ground so that the granules can progressively break down.

Pros:

  • Dry products are the most budget-friendly option for plant nutrition.
  • They’re simple and easy to use, which makes them perfect even for beginners.
  • They require minimal storage space and have an extended shelf life.

Cons:

  • Misuse can lead to runoff or damage to plants and the surrounding ecosystem. Always follow the specific instructions written on the packaging to avoid causing harm.

Controlled-release fertilizers

Controlled-release fertilizers, also known as CRFs, are used on all sorts of crops around the world, from veggies to flowers. These are slow-acting products that typically come in granular form and are based on nitrogen.

Controlled release technologies were first developed back in 1936 and hit the market in 1955. Since then, there have been many new variations of CRFs, which vary depending on the crop, the nutrients needed, and how long you want the release to last. So, do your research and look up the requirements of your plants before picking up one of these fertilizers.

Pros:

  • For the majority of growers that use CRFs, it’s a choice made out of environmental concerns. Slow-release fertilizers are generally less harmful than conventional products.
  • Some agriculturists suggest that CRFs can lead to higher crop yields and superior-quality produce.
  • CRFs contribute to more uniform growth in plants.
  • Slow-acting products are often designed following new regulations aimed at reducing nitrogen losses.

Cons:

  • CRFs are a more costly initial purchase than traditional fertilizers.
  • External factors, such as weather conditions and soil temperature, can still affect the release rate.
  • You may need to add a supplementary fertilizer because CRFs may not provide all the necessary nutrients in the desired ratios.

Powder fertilizers

Powder formulas are versatile, water-soluble fertilizers that are applied during irrigation or as a foliar spray. Diluting the product makes it easier for plants to take in the nutrients, so they’re much more efficient too.

You can find powder fertilizers in both synthetic and organic forms. Bat guano, alfalfa meal, and dried kelp are only a few of the natural options available on the market. And guess what? They’re a better deal, too! They cut down on plastic packaging and save on transportation costs, compared to liquid or pre-mixed products.

Pros:

  • Because the fertilizer is in a small powder-like form, it mixes nicely with the soil and is easily absorbed by the plants’ roots.
  • Generally considered to be safer for the environment when used in moderation.

Cons:

  • Timing is key! Application rates vary greatly depending on the phase of development of the crop.
  • Powders dissolve in water, but they can also create dust particles in the air, which may worry some people.

Liquid fertilizers

Precise, fast-acting, and water-soluble—the perks of liquid fertilizers are hard to replicate in solid form.

If you’re a hobbyist, this is probably the type of fertilizer you’re most familiar with. Most of us already use a watering can or hose to irrigate our houseplants and garden containers. That’s why diluting fertilizer in water is the easiest way to feed your plants.

However, plenty of professional growers swear by liquid fertilizers as well. This is specifically due to their rapid results. Plants absorb moisture through their leaves or roots, which is much faster than waiting for granules to decompose into the soil.

Pros:

  • Liquids are available in concentrated forms or convenient hose-end bottles for easy mixing and application.
  • Because there’s a lower risk of overfeeding, you can use liquid fertilizers more frequently.
  • They are suitable for all sorts of growers—from newbies to professionals. For large-scale farming, using a fertigation system is the way to go.

Cons:

  • Requires more time for application compared to dry fertilizers.
  • Because the effect of liquids is dependent on consistent watering, it adds an extra layer of maintenance.

Gel fertilizers

Here’s an innovative alternative that might have slipped your radar. Gel fertilizers are a viscous specialty product that comes in a highly concentrated form.

Hydrogels are made of polymers that soak up and retain moisture. Alongside NPK, gels also contain chelated microelements. What are those, you may ask? Well, these are unique minerals that bind to molecules that plants rapidly absorb. Micronutrient fertilizers in gel form are a complementary type of nutrition. They’re meant to add extra trace elements into the soil during various growth stages.

Pros:

  • Hydrogels are soluble in water and come in a huge variety of nutrient compositions.
  • Gels are just as effective as dry fertilizers, but with way less impact on the environment.
  • Gels slowly supply crops with water and nutrients over time. This delayed mechanism solves some of the common problems you get with granular or liquid types.
  • Gel fertilizers improve soil structure and encourage healthy microbial activity.

Cons:

  • Generally more expensive compared to traditional types of fertilizers.
  • Because they’re a specialty product, you may not find them in general stores.

Nitrogen fertilizers

We’ve covered the different formulations, and now it’s time to move on to the most popular fertilizer types based on their nutrient content.

Let’s start with explaining the N in NPK, or the role of nitrogen in plant growth.

Nitrogen is all around us. It’s in the air we breathe, and plants need it for chlorophyll production and photosynthesis. If you want to see leafy, lush foliage in your garden, check out the nitrogen content in your soil.

Two major types of products fall into this category: urea and ammonia.

Urea is the most commonly produced and used fertilizer worldwide. It’s easy to make, highly potent, and cheap to transport and store for the amount of nitrogen it provides.

But here’s the thing: plants can’t use urea directly. It needs to be converted into ammonium and nitrate first before crops can absorb it. Ammoniacal fertilizers, on the other hand, are a readily available source of nitrogen.

Pros:

  • The most popular type of fertilizer. Corrects nitrogen deficiency, which can cause stunted growth, chlorosis (yellowing), and reduced yields.
  • Plants need nitrogen for amino acid formation, DNA, and other vital compounds.
  • No need to worry about variety—there are plenty of inorganic and organic nitrogen sources.
  • Hydrogen has the potential to become one of the “greenest” sources of fertilizers and clean energy.

Cons:

  • The high solubility of nitrogen fertilizers can lead to leaching and water pollution.
  • Overapplication causes plant toxicity and harms soil health.
  • Most manufacturing processes still largely depend on fossil fuels.

Phosphorus fertilizers

Do your crops have spindly stems and discolored leaves? This might be a sign of phosphorus deficiency.

The second letter in NPK stands for phosphorus, an element that plants rely on for cell division and protein synthesis. Seedlings and young plants, in particular, need a healthy amount of it to develop strong roots, beautiful blooms, and seeds.

Phosphorus fertilizers come in many forms, each with varying content and solubility. You can choose between naturally sourced or synthetic products too. Take rock phosphate, for instance. It’s a relatively cheap organic mineral that drastically improves soil structure.

Pros:

  • Phosphorus is integral to photosynthesis, so that plants can transform sunlight into chemical energy.
  • Helps in hastening plant maturity and is particularly effective as a starter fertilizer ingredient.
  • Phosphorus is relatively immobile in the soil. Thus, it will not leach as much as nitrate and sulfate.

Cons:

  • The cost of these types of fertilizers is volatile due to the limited supply of sources such as phosphate rock and guano.
  • Phosphorus binds to soil particles and may not distribute evenly.
  • Organic products are not as efficient. You may need to apply them more frequently to yield any significant results.
  • Phosphorus deficiency is difficult to diagnose early, and once visible, it may be too late to correct in some crops.
  • Test your soil acidity because it affects phosphorus availability to plants. Optimal pH levels are between 6 and 7.

Potassium fertilizers

The third most important element for plant life is potassium (K). Without it, crops are much more susceptible to withering due to stress and diseases.

It’s especially important if you’re growing fruits and vegetables. Potassium is known for improving the taste, appearance, and shelf life of produce.

Potash, specifically, is a well-known group of potassium-based minerals. It’s a finite resource, and nearly all of the mined ore goes into fertilizer production.

But potassium isn’t just important for plants; our bodies need it as well. However, we don’t store it, so we have to keep getting it regularly from potassium-rich foods, such as apples, spinach, and bananas.

Pros:

    • Potassium contributes to the formation of cellulose and encourages metabolic activity.
    • Encourages the movement of sugars and starches within the plant.
    • It regulates photosynthesis by controlling the opening and closing of stomatal pores, which are tiny openings on the surface of leaves.
  • Activates over 60 essential enzymes that support plant growth.

Cons:

  • We are extracting more potassium from our harvests globally than we are replenishing. This is called soil-nutrient mining
  • Too much potassium in the soil can make it harder for plants to take in magnesium.
  • Overapplication can lead to waterlogging, which makes it harder for plants to get the nutrients they need.

Starter fertilizers

As you can probably guess by the name, starter fertilizers are applied during planting. Usually, they’re meant to give seeds, saplings, and propagules an initial boost of energy. They help baby plants develop strong roots, especially when the soil is cold or wet, or if you’re planting without tilling the soil.

We mentioned earlier that phosphorus is a primary component of most starter fertilizers. However, these products usually come in various blends of micronutrients and trace elements meant to encourage germination.

When applied, the starter should be positioned 2 inches to the side and 2 inches below the seed. This is a common practice meant to prevent fertilizer burns in the developing root system.

Pros:

  • Starter fertilizers encourage early seedling growth and root development.
  • Especially useful for crops that have high nutrient demands early in the growing season, such as wheat and corn.
  • Aids in quicker crop establishment, particularly in challenging soil conditions.

Cons:

  • Applying this kind of fertilizer requires additional equipment and attachments. As a result, starter treatments raise the costs of the farming process. 
  • Long-term yields vary based on soil fertility.
  • Potential risk of damaging your plants if not applied correctly.

How to Choose the Right Type of Fertilizer

We have only scratched the surface of the many types of fertilizers out there. But now let’s move on to the practical question at hand: which kind of product is right for you?

For starters, you’ll probably want to decide if you’ll go for an organic or chemical option. You can refer to the table we shared at the beginning of this blog post to compare the two. Your decision will depend on the kind of plants you’re growing, the size of your operations, and, of course, your budget.

As for which type of formulation you should go for, here are our rule of thumb recommendations:

  • Go for a granular fertilizer if you have larger fields and want the best results at the lowest cost per acre. Their effect is long-lasting too, so you won’t need to apply them as often.
  • Liquid fertilizers are fast-acting and much easier to handle. Simply dilute them in water before you irrigate your plants. Choose this beginner-friendly option if you’re a hobbyist or want to fertilize your indoor houseplants.
  • Gel formulations are specialty products meant for professional fertilization. Gels are slow-acting, and plants easily absorb the chelated microelements they provide. Use them if you’re aiming for precise nutrient regulation.

And here’s one extra tip from us: if you’re unsure about the supplements your plants need, a soil test will help you pinpoint any deficiencies. There are DIY kits you can use, but for the most accurate results, grab a sample and send it to your local lab.

Not sure which type of fertilizer to choose? Our experts are ready to assist you today. Reach out to us for personalized advice!

How to Read Fertilizer Labels

If you’ve ever picked up a bag of fertilizer from your local garden center, you’ve probably noticed three numbers on the label. No, it’s not just random codes—these indicate the fertilizer’s NPK ratio. So if the packaging has 20-10-10 written on it, it means the fertilizer contains 20% nitrogen, 10% phosphorus, and 10% potassium.

Let’s say, for example, you did a soil test and the results show your yard lacks nitrogen but has plenty of the other two macroelements. In this case, you need to add nitrogen, so opt for a fertilizer with a higher first number (nitrogen).

But remember, more isn’t always better! Overdoing it with fertilizer can actively harm your plants and their habitat. Follow the application guidelines given by the manufacturer to get the maximum effect out of the product.

Conclusion

We hope this guide was as useful as it was informative. With so many options out there, it can be difficult to pick the right type of fertilizer for your plants. But now you should be able to confidently make your choice! And if you’re feeling extra adventurous, you could try making your own homemade organic fertilizer. Whichever type you go for, use it consciously, so we can all enjoy growing and reaping the fruits of our labor with love and care for the environment.

FAQ

What are the best types of fertilizer?

There are different types of fertilizers for a reason: there is no universal product. However, most growers suggest using a balanced NPK fertilizer with a bit more phosphorus. For example, a 10-20-10 or 20-20-20 ratio should work well, and these are sold at most garden centers.

What type of fertilizer do farmers use?

Farmers use many different types of fertilizers, organic and inorganic, each with its pros and cons. Dry nitrogen fertilizers are the most widespread products, followed by potash and phosphate.

What is the most commonly used fertilizer?

Urea, a nitrogen-based product, is the most commonly used fertilizer worldwide. Urea is highly effective, cost-efficient, and provides a readily available source of nitrogen for plants. It is widely used in both commercial agriculture and home gardening.

What are the five fertilizers?

Fertilizers can be broken down into five major categories: organic, inorganic, slow-acting or controlled-release, dry or granular, and liquid or water-soluble. There are more types of fertilizers out there, but these are the most popular ones.

Sources:

https://www.statista.com/statistics/1288255/global-consumption-of-nitrogen-fertilizer-by-product/

https://www.farmprogress.com/crops/specialist-offers-info-on-phosphorus-fertilizer

https://www.cropnutrition.com/nutrient-management/potassium/

Article by:

Krasimir Bozhurin

Krasimir Bozhurin is the Sales Director at Vaki-Chim LTD. With over a decade of experience in the trade of fertilizers, preparations, and seeds, he has developed extensive expertise in the cultivation of perennial fruit plantations and cereal crops.