How Fertilizers Work

The easiest way to understand the significance of fertilizers is to view them as food for plants and crops. Just as people need an adequate and consistent diet to grow and stay healthy, plants and crops have to get proper nutrition from the soil to thrive.

The menu for plants must include a balanced supply of nitrogen, phosphorus, potassium and sulphur. As plants and crops extract these nutrients from the soil during every growing season, they must be replenished through fertilizers, manure and compost added to fields or gardens annually.

The advantage of using fertilizers is that they can be applied with more control to match crop needs and protect the environment. Or they can supplement manure or compost to ensure the soil gets an adequate supply of nutrients. For that reason, the Canadian Fertilizer Institute and agriculture organizations stress the importance of managing and balancing the supply of nutrients to prevent both over and under-fertilization.

Fertilizers are composed of the same ingredients as manure and compost. Added to the soil, they make nutrients easily available to plants and crops. Nitrogen, which is essential to plant growth, is extracted from the atmosphere. Air is about 78% nitrogen so fertilizer companies have a readily available supply of it. Phosphorus comes from fossil remains found in phosphate rock, and potash fertilizers come from ancient seabed deposits.

Research has shown that the protein, vitamin and mineral content of our food are boosted by the nutrient content of the soil. For example, potash fertilizer improves the isoflavone content of soybeans, which has been known to help prevent health problems such as cancer of the colon, breast and prostate, and most recently, the potential to reduce blood cholesterol.

The following table shows how common nutrients benefit plants and people

Keeping food producing soils healthy is important in our world where one in seven people go hungry and one in three are short of minerals and vitamins. While people in other countries often spend more than half of their income on food, Canadians use about 10% of their income to feed themselves. In part this is because our farmers can produce the most abundant, affordable and nutritious food in the world with the help of fertilizers.