Five important facts about fertilizers

In December 1905, Sam Eyde and Kristian Birkeland successfully produced nitrogen fertilizer at Notodden, Norway. This groundbreaking achievement has helped increase agricultural productivity and today, half of the world’s population has food on their table due to fertilizers. Here are five important facts you should know about fertilizers and their importance in safeguarding lives and nourishing our world!

Hand applying fertilizer to soil
Hand applying fertilizer to soil

Last updated: October 12, 2023

Fact 1: Fertilizers do not deplete the soil

Fertilizers are key to rejuvenating the soil by providing nutrients the plants need to grow healthily.  

In nature, there are 17 critical plant nutrients: the macronutrients nitrogen, phosphorus, potassium, calcium, sulphur, magnesium, oxygen, hydrogen, carbon, and the micronutrients iron, boron, chlorine, manganese, zinc, copper, molybdenum and nickel.

When crops are harvested, the nutrients follow the crop. Important nutrients are therefore removed from the soil. Often the soil is not able to replenish all the nutrients by itself, that is where fertilizers are crucial in supplying the nutrients that are lacking. In turn, this maximizes crop yield and quality.  

In the US alone, the average corn yields have more than doubled since 1968(1), through more effective farming.  

Both organic and mineral fertilizers can be used to replenish the soil. While the nutritional content of organic fertilizers can be inconsistent, influenced by soil health and climate, mineral fertilizers offer high nutrient concentration and immediate availability. However, as mineral and organic fertilizers complement each other, a comprehensive nutrient program should incorporate both.

Fertilizers maintain soil fertility

"Fertilizers are essential for reducing deforestation, rejuvenating soil health, and ensuring sufficient food production for a growing global population." 

Ole-Jacob Siljan, Plant Manager at Yara Porsgrunn


Fact 2: Fertilizers are made of natural elements

All the nutrients contained in different fertilizers are found in nature.

The most common sources of nutrients in mineral fertilizers are nitrogen, potassium and phosphate. These natural sources are processed industrially and transformed into mineral fertilizers.

Nitrogen makes up 78 percent of the air we breathe, but plants cannot get it directly from the air - they need to take it up through the roots from the soil.

The most common process in nitrogen fertilizer manufacturing is to create ammonia from a mixture of nitrogen from the air and hydrogen from natural gas. 

Potassium is sourced from old sea and lake beds formed millions of years ago. Since potassium sources are often located far below the soil surface (1-2km depth), plant roots are unable to reach them naturally. 

Potassium fertilizers are based on naturally occurring potassium chloride. This is somewhat similar to table salt – sodium chloride. 

The ash from burning wood or straw is high in potassium, this is where the name ‘potash’ originates. 

Phosphate is sourced from insoluble calcium phosphate rocks – often referred to as “rock phosphate”. In this form it is not available to plants. Rock phosphate is made available for the plant usually through a chemical process to create plant friendly fertilizers. 

Man holding a fertilizer prill

Nitrogen (N), phosphate (P), and potassium (K) can also be combined to form NPK compound fertilizers, that provides the crop with the three major nutrients at the same time.

Like mineral fertilizers, organic fertilizers are also made of natural elements - or materials with a biological origin. These include animal wastes, crop residues, compost, biosolids and more.


Fact 3: Fertilizers are not the same as pesticides

"The most prevalent misconception is the belief that mineral fertilizers are pesticides and are considered harmful or poisonous," says Ole-Jacob Siljan, Plant Manager at Yara Porsgrunn, home to the world's largest NPK fertilizer production facility.

Pesticides are synthetic or natural chemicals used to control pests. Pesticide is a commonly used term for all crop protection chemicals, which also include fungicides that control fungal diseasesand herbicides that control weeds.

Fertilizers, on the other hand, supply natural nutrients to make crops grow.

The role of fertilizers is to increase yield and ensure healthy produce by supplying the right balance of nutrients to the soil.


Fact 4: Fertilizers do not alter the plants we eat

Fertilizers do not alter the DNA of crops. Instead, they improve the growth and quality of the crop by adding important nutrients.

The amount of nutrients added is chosen by the farmer after analyzing the soil and determining the requirements of individual crops. 

Fertilizing in the correct way can have a great impact on crops' yield, appearance and nutritional value.

Tomato trees with and without nutrient deficiency
Fertilizer adds nutritional value: To the right, tomato plant with nitrogen deficiency, to the left, tomato plant with optimum nutritional balance.


Fact 5: Fertilizers do not make you ill

Eating crops from a fertilized field, or meat from animals that have grazed on a fertilized pasture, does not pose any health risks for animals or humans.

On the contrary, the nutrients in the fertilizer required for crop growth, are the same nutrients required for human growth and development. 

Fertilizers are critical to the quality and nutritional properties of the food we rely on.

Mineral fertilizers serve as a vital source of nutrients for soils, livestock, and ultimately, human consumers. Without the precise and balanced application of mineral fertilizers to ensure plants receive the necessary nutrients, resulting food may lack the crucial nutrition required for human health and wellbeing.

Woman selling fresh produce in vegetable market

Ultimately, careful fertilizing can help combat disorders caused by malnutrition.

In countries where specific nutrient deficiencies are a problem, fortifying fertilizers with the relevant micronutrients have also helped better the health of large populations.

Zinc and selenium are two examples of minerals that have been successfully applied to fertilizers to combat deficiencies in large populations.


External resource:

1 - Historical Corn Grain Yields for the U.S. (Purdue University website/Corny News Network)