It’s common knowledge that fertilizers give your plants an extra boost, but how? In this article, you’ll learn basics on fertilizers, what an NPK ratio is, and five reasons why an organic fertilizer is the best choice for savvy growers.

What is Fertilizer?

Fertilizer and Soil with Farm Spade
Most fertilizers contain the Big Three macronutrients, including nitrogen, phosphorus, and potassium. The main differences between synthetic and organic fertilizers are how available these nutrients are to the plant, and also what other nutrients are present.

Fertilizers are natural or synthetic products that contain the essential nutrients for your plants to grow. Most commonly, fertilizers contain potassium, nitrogen, and phosphorus; commonly known as the Big Three macronutrients.

In A Beginners Guide to Soil Nutrients, we talked about how each of these three nutrients plays a part in plant growth. The other macronutrients– carbon, hydrogen, and oxygen – are easily accessible by plants from air and water, so they aren’t required for soil supplementation.

Modern fertilizers also take into account micronutrients, which are equally as important for plant growth and development. To learn more about these lesser-known key ingredients, visit A Deeper Look at Soil Nutrients.

At first glance, fertilizers seem quite simple. Our ancestors used fertilizer to grow successful crops approximately 8000 years ago, without having the science to back up their decisions. Animal manure has been a staple fertilizer for centuries; however, we’ve only recently discovered its value for the plant, soil, and microbial community. 

To start, let’s take a look at the composition of fertilizers.

NPK Values

Small Plant closeup in fertilizer soil with sunlight
Nitrogen is an essential plant nutrient, obtained through biological processes in the soil and soil supplementation. Without nitrogen, plants wouldn’t be able to use sunlight in photosynthesis.

When buying fertilizer, all of them will contain three big numbers, know as the NPK value. Nitrogen content is the first number, phosphorus the second, and potassium the third. For example, a fertilizer with an NPK value of 20:5:10 means that the bag contains 20% nitrogen, 5% phosphorus, and 10% potassium by weight. The rest of the ingredients are usually inert (don’t have any effect); however, in some cases, additional nutrients are added in.

All of the NPK nutrients are essential for plant growth. Nitrogen, for example, is naturally supplied to plants through microbial interactions in the soil, but not enough to feed our growing population. Nitrogen supplementation is critical, supplying approximately 50% of what’s required for global food production.

Nitrogen is a component of chlorophyll, the compound that allows plants to turn sunlight into sugar for energy. Nitrogen is vital to plant health, but it does have its limits within the soil. Too much nitrogen can have negative health and environmental impacts.

To mitigate the risk of too-much-of-a-good-thing, it’s important to choose the right kind of fertilizer. This choice depends on the type of crop you’re growing, the geographical location, and the health of your existing soil. There are many options to choose from, separated into two main categories: synthetic and organic.


Should I Use a Synthetic or Organic Fertilizer?

Earthworm in Compost Soil as Fertilizer
Earthworms are efficient composters that create potent, organic fertilizers. Some other forms of organic fertilizers include manure, bone, feather, and kelp meal.

The arguments for choosing synthetic fertilizers are usually price and effectiveness. Organic options can be more expensive, and synthetic choices can be faster-acting. However, this is not always the case. New research is bringing to light the longterm benefits of organic growing, including increased efficiency. 

To make an educated choice between synthetic and organic, let’s start by identifying the differences. Organic fertilizers are those made directly from plant or animal sources. These fertilizers are often in the form of manure, compost, or bone meal.

Inorganic or synthetic fertilizers are chemically manufactured supplements that contain growth-enhancing macronutrients. Synthetic fertilizers are usually only NPK in composition, but they can have additional micronutrients added to their mix.  

What’s the Difference Between Inorganic and Organic Fertilizer?

The key difference between the two is how quickly nutrients are available for your plant to use. Inorganic fertilizers have nutrients in forms that are immediately available, while organic fertilizers slowly release those nutrients to your plants.

Wait a second. Don’t we want our plants to have those nutrients immediately?

Actually, no. There are multiple reasons why a sudden shock and quick delivery of growth nutrients can be harmful to your plant. An organic fertilizer allows for steady growth, giving time for optimal plant development at every stage. In turn, crops show increased flavour, aroma, and potency. 

Organic Fertilizers vs. Fertilizers Containing Organic Compounds

Large Truck Throwing Out Fertilizer on a muddy crop soil
Organic fertilizers and fertilizers with organic compounds are not the same! It’s important to know the difference to spot sneaky synthetic fertilizers pretending to be all-natural.

When choosing an organic fertilizer, it’s important to watch for sneaky wording around organic compounds.  In chemistry, organic compounds are simply molecules that contain carbon. This classification is broad and can encompass a variety of materials, including plastics and gasoline. 

Organic compounds in fertilizer don’t necessarily come from organic biological matter either. In fact, one of the most common fertilizers on the market is synthetic urea. In soil, urea is rapidly converted to ammonia and can be highly volatile. This organic compound is used to deliver nitrogen quickly to plants, a red flag for being an inorganic fertilizer.


The Problem with Synthetic Fertilizers

At BlueSky Organics, we believe in the many benefits of choosing organic fertilizers. Here are five reasons why inorganic fertilizers come up short:

They can be missing key ingredients

Fertilizers are meant to supply the missing pieces for optimal plant growth, but synthetic fertilizers often only focus on the Big 3 macronutrients. Having a variety of macro and micronutrients is essential in proper plant development. NPK values are usually what inorganic fertilizers focus on, whereas organic fertilizers provide a balanced nutrient profile.

Lake with farm fields in the background at dusk
Synthetic fertilizers tend to deliver too much nitrogen, too quickly. This often results in leftover nitrogen being transported away from the plant roots and into other water sources, such as our lakes and rivers.

They can scorch and “burn” your crop

The bioavailability of synthetic fertilizer macronutrients is high. This means that after application, your plant will take up as much as possible. Like eating at a buffet, having too much accessible food around you can lead to some, um let’s say, unfortunate consequences.

Leaf scorch is a term used to describe the symptoms of overfertilization. When your plant is shocked with high amounts of any nutrient its roots can be “burned”. For example, nitrogen-heavy fertilizers will quickly make your plant look greener as the plant creates more chlorophyll, but that green will not last. Too much nitrogen will lead to nutrient lockout, and over time leaves will start to show scorched symptoms.

Organic fertilizers are “non-burning” as they contain nutrients that are broken down over time and slowly released into the soil. This also prevents loss of the nutrients to the environment, such as chemical runoff into lakes and rivers.

They kill beneficial microbes

Soil is full of microorganisms that work in harmony to help your plant thrive. Many of these organisms are responsible for converting organic nutrients into a form that your plants can use, with mutually beneficial relationships that promote healthy plants and soil.

Most inorganic fertilizers don’t contain organic matter, which is needed for creating microbial products. In fact, the immediate availability of nutrients such as nitrogen can actually overwhelm the natural balance in the soil. This could lead to a loss of biodiversity and soil health.

You may be starting with healthy soil, but if you damage the microbial community, soil and plant health will inevitably suffer.

“The more we pour the big machines, the fuel, the pesticides, the herbicides, the fertilizer and chemicals into farming, the more we knock out the mechanism that made it all work in the first place.” – David R. Brower

Tractor Fertilizing Green Crops
Inorganic fertilizers are often nitrogen-heavy, risking dramatic changes in soil pH and structure.

They can change your soil

Synthetically-sourced nitrogen, phosphorus, and potassium compounds are known as salts. These nutrients are chemically derived and manufactured. High concentrations of salts can lead to acidification, lowering the pH of the soil. A low pH has many negative consequences for plant health, including cannabis plants, that prefer a pH of 5.5-6.

Most inorganic fertilizers are nitrogen-heavy, risking dramatic changes in soil pH. Organic fertilizers, in contrast, don’t change your pH as drastically, as the nutrients slowly released. They also don’t form a crust on your soil, allowing more oxygen to enter the soil. A stable pH and oxygen flow are important for soil microbes, improving water movement and adding to soil structure as well.

They are terrible for your wallet

BlueSky Organics Fert-Alive Container
Fert-Alive™ is an organic fertilizer that promotes the growth of beneficial microorganisms and improves nutrient uptake.

Inorganic fertilizers are usually water-soluble. This means that excess nutrients will wash out and leave the soil quickly after application. You’ll have to keep buying these fertilizers over and over again, reapplying them multiple times to your soil.

More work and higher costs? No thank you!


What Blue Sky Organics Can Offer 

BlueSky Organics Fert-Alive is an organic fertilizer designed to give your plants the nutrients it needs. It keeps nutrients locked into your soil, and feeds beneficial microbes to keep your soil happy. 

You won’t have to worry about nutrient lockout with this ready-to-use and easy-to-apply fertilizer. When you know what to look for in fertilizer and use our helpful growing guide, quality growing is a breeze!