Frequently Asked Questions

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Thanks to the Nutrients For Life Foundation for sharing FAQs

Fertilizer Fundamentals

What is fertilizer?
Simply put, fertilizer combines the nutrients that plants need to grow — potassium, nitrogen, and phosphorus — in a form they can digest. Think of it as plant food.

As crops grow, they absorb, or mine, nutrients from the soil. When crops are harvested, so too are the nutrients absorbed by plants. Commercial fertilizers nourish the soil by returning the “food” that next year’s crop will require.

Nitrogen is a key element in protein. Like the human body, plants need it to grow. Phosphorus is the plant world’s equivalent of carbohydrates – it provides the energy for plants to thrive. And potassium is a mineral that helps plants fight stress and disease. It helps plants grow strong stalks, in the same way that calcium gives people strong bones.

Are there chemicals in fertilizer?
The three main ingredients in fertilizer — nitrogen, potassium, and phosphorus — come from nature. They are not man-made. Fertilizer companies simply convert them into a form that plants can use.

Fertilizer producers can blend nutrients into precise combinations to match the unique needs of different farms, crops, and fields. In this way, farmers can feed their soils with the most effective and efficient blend of potassium, phosphorus, and nitrogen to achieve optimal yields.

Do farmers need to use fertilizer?
In a word, yes. Every season, plants draw from the soil the nutrients they need to grow. When a crop goes to market, so too does the potassium, phosphorus, and nitrogen it has absorbed and used throughout the growing season. When farmers fertilize, they put back into the soil the nutrients their next crop will require.

Soils do not naturally contain all the nutrients that crops need. And while some of the same nutrients in fertilizer are found in soil, they are not present in a sufficient supply for today’s high-yield farming.

It can take years — even decades — for nutrients to build up in the levels necessary to nurture a good crop. A single season can wipe out many years’ worth of naturally produced nutrients. Fertilizers give Mother Nature a helping hand.

Where does phosphorus come from?
Phosphorus used in fertilizers comes from the fossilized remains of ancient marine life found in rock deposits in the U.S. and other parts of the world. This raw ore is processed to create water-soluble compounds that make the phosphorus available to plants as a nutrient.

Phosphorus helps early plant health and root growth. It is involved in seed germination and ensuring plants use water efficiently. Phosphorus is the plant world’s equivalent of carbohydrates — it provides the energy that a plant needs to grow.

Where does potassium come from?
Potassium is the seventh most abundant element in the earth’s crust. Through natural processes it is filtered into the planet’s seas and oceans. As these bodies of water evaporate over time, they leave behind mineral deposits. Fertilizer companies mine potassium from these deposits.

Potassium is a mineral that helps crops fight stress and disease. It helps plants grow strong stalks, in the same way that calcium gives people strong bones.

Where does nitrogen come from?
The air all around us contains huge amounts of nitrogen. In fact, nitrogen makes up about 78% of the atmosphere. Fertilizer producers combine nitrogen with natural gas to change it into a form that plants can digest.

Nitrogen is nitrogen, whether it’s used by plants, animals, or people. It is a key element in protein. Like the human body, plants need nitrogen to grow. Often used in greater amounts than other nutrients, nitrogen helps make plants green and plays a major role in boosting yields.

What are the essential mineral nutrients?
- Macronutrients: nitrogen, phosphorus, potassium, calcium, magnesium and sulphur
- Micronutrients: boron, chloride, copper, iron, manganese, molybdenum, nickel and zinc
- Essential or beneficial for some plant species, not all: silicon, sodium, cobalt
- Essential for animals but not for plants: selenium

Fertilizer & Food

What role do fertilizers play in feeding a growing world population?
Fertilizers play a huge role in helping feed the world. Thanks to modern fertilizers, world food production has more than doubled since 1960. Today, an estimated one-third to one-half of our global food supply is directly linked to use of commercial fertilizers.

If we are to meet growing demand for food, however, we will need to double our current levels of production. We can’t do that without fertilizers. Just to match current production, we’d have to put into production every available acre outside urban areas — including forests, wildlife habitats, and leisure areas.

In Canada, an estimated 40% of yield increases achieved by farmers are a direct result of commercial fertilizers. Continuing to make better and more efficient use of fertilizer will help us feed the planet.

What would happen to food prices without fertilizer?
One of the biggest benefits from efficient fertilizer use is inexpensive food. Worldwide, one in three people can neither grow nor afford to buy enough food. With the help of commercial fertilizer, North American farmers are able to produce the most abundant, nutritious, and affordable food on the planet. In fact, it’s one of the main reasons why people on this continent spend less for food than any other nation on earth.

While people in other countries spend between 15% and 50% of their income for food, U.S. citizens spend only about 10%. Much of this abundance can be directly linked to efficient use of commercial fertilizer. Without it, food would cost all of us a lot more.

Aren’t organic foods better, because they’re grown without fertilizer?
Actually, most organic growers use fertilizer too. It’s made from different ingredients though, such as livestock manure or sewage sludge. However, these natural fertilizers are not available in sufficient quantities to meet the demands of today’s high-yield farming, nor do they provide nutrients in the fine-tuned combinations possible with commercial fertilizers. For example, using enough manure to provide an adequate supply of nitrogen would mean adding four to five times more potassium and phosphorus than a crop needs. So it’s easy to over- or under-fertilize in this type of farming.

As well, organic crop yields are only one-third to one-half as high as those from farms using conventional fertilizers. So we’d need to turn millions more acres of land over to farming, and still end up with less food.

As for the notion that organically grown foods are better for you, there is simply no proof. Even leaders of groups such as the Organic Trade Association and knowledgeable organic growers themselves don’t make these claims — they know there isn’t any evidence to back it up.

Fertilizer and the Environment

Is fertilizer harmful to environment?
Commercial fertilizer has become an indispensable tool in today’s high-yield farming. Its misuse, however, can damage our environment. Fortunately, advances in agricultural techniques are enabling farmers to apply soil nutrients with pinpoint accuracy, minimizing or avoiding altogether any damage to soil, water, and air.

New soil sampling and tillage methods, use of starter fertilizers, and better timing and placement of nutrients mean producers are getting more bang for the buck from fertilizer. For example, farmers today are producing one-third more corn for each pound of nitrogen they apply, compared to 20 years ago.

Commercial fertilizer is also helping to conserve land. Without it, we’d be forced to plow up parks, wildlife habitats, and parks so we could produce enough food to feed the world’s growing population. And by improving plant nutrition, fertilizers help reduce global warming. Experts estimate that American crops give off as much as 500 million tons of oxygen every year.

Wouldn’t it be better for the environment to use less fertilizer?
As a result of advances in agricultural practices, farmers have been cutting back on the amount of fertilizer they use. We’ve made great strides in gaining maximum efficiency from the amount we do apply. There’s a fine line though, between using just the right amount of fertilizer, and not replenishing the nutrients needed to keep pace with today’s high-yield farming.

Last year, farmers only replaced 75% of the phosphorus their crops removed from the soil, and just over 50% of the potassium plants used. More of both nutrients are needed, or yields will fall.

But that’s not the only problem associated with depleting nutrient reserves. An insufficient supply also saps plants’ ability to withstand harsh weather, disease, and other stresses. Nutrient-starved plants cannot maintain soil moisture, which leads to soil erosion from wind or water.

Although dry weather played a key role in the “dust bowl” conditions of the 1930s, insufficient levels of nutrients were at the root of the vicious cycle of problems that plagued Depression-era farmers. Plants could not help the soil hold enough moisture, which in turn caused increased wind erosion.

Isn’t organic farming better for the environment, since it doesn’t use fertilizer?
Most organic growers use fertilizer too. It comes from different ingredients, such as livestock manure or sewage sludge.

However, these natural fertilizers are not available in sufficient quantities to meet the demands of today’s high-yield farming, nor do they provide nutrients in the ideal balance made possible with commercial fertilizers. For example, using enough manure to provide the soil with an adequate supply of nitrogen would mean adding four to five times more potassium and phosphorus than a crop needs. So it’s easy to over- or under-fertilize in this type of farming.

As well, organic crop yields are only one-third to one-half as high as those from farms using conventional fertilizers. So we’d need to turn millions of additional acres of land over to farming, and still end up with less food.

What is runoff from fertilized land doing to our lakes and streams?
It’s true that phosphorus and nitrogen can harm water quality. Thanks to advances in agricultural techniques though, farmers are now able to precisely tailor nutrient amounts to their specific soil conditions — so nutrients are either taken up by crops or stay in the field.

The foundation and others in the fertilizer industry are committed to promoting practices that protect and enhance the environment, including use of conservation buffers. These strips of land along the edges of bodies of water are planted with permanent vegetation designed to slow runoff and soak up nutrients before they run into streams, lakes, and rivers. Studies have shown that these buffers can remove more than 50% of nutrients in runoff from farms.

Fertilizer and Soil

If there are already nutrients in the soil, why add more?
When farmers use fertilizer, they are not adding nutrients to the soil. Rather, they are replacing what has been absorbed by plants. Each growing season, crops “mine” from the earth the potassium, nitrogen, and phosphorus they need. At harvest time, these nutrients go to market along with the plants, leaving a shortage for next season’s crop. By fertilizing their land, farmers are simply completing the ongoing cycle. This recycling of nutrients ensures that subsequent crops get what they need to grow.

Soils do not naturally contain all the nutrients that crops need. And while some of the same nutrients in fertilizer are found in soil, they are not present in a sufficient supply for today’s high-yield farming.

It can take years — even decades — for nutrients to build up levels necessary to nurture a good crop. A single season can wipe out many years’ worth of naturally produced nutrients. Fertilizers give Mother Nature a helping hand.

If yields are increasing, we must be using more fertilizer, right?
We’ve made great strides in using fertilizer more efficiently and effectively. Last year, American farmers produced food for 26% more people than they did in 1980, but used less commercial fertilizer than 20 years ago.
Our use of nitrogen — the main fertilizer ingredient for most crops — has been dropping steadily since 1994. Farmers used less of it last year to produce 50% more corn than in 1980. Similarly, use of phosphorus was down 11% last year, compared to its peak in 1977.

Although crop yields are increasing, this is more as a result of new and improved farming practices — including soil sampling, use of starter fertilizers, and more precise timing and application of fertilizer. These changes have enabled farmers to produce three times the yield using about the same number of acres of farmland as they did in 1960.

Wouldn’t it be better to err on the side of under-fertilizing?
Today, farmers are producing higher yields using less fertilizer. However, tests have shown that nearly half of North America’s most productive soils do not currently contain the nutrients necessary to keep pace with growing world demand for food.

Farmers have been depleting reserves of soil nutrients rapidly in recent years. Last year farmers replaced only 75% of the phosphorus that their crops removed from the soil, and replenished just over 50% of the potassium. Without more of both nutrients, yields will decrease.

But that’s not the only problem. An insufficient supply of nutrients also saps plants’ ability to withstand harsh weather, disease, and other stresses. Nutrient-starved plants cannot maintain soil moisture, which leads to soil erosion from wind or water.

While drought conditions were largely to blame for the "dust bowl" of the 1930s, insufficient levels of nutrients were at the root of the vicious cycle of problems that plagued Depression-era farmers.

What happens to fertilizer when a crop is harvested?
When a crop goes to market, so too do the nutrients that plants have absorbed from the soil. If farmers don’t replace the nitrogen, potassium, and phosphorus this year’s crop has used to grow, next year’s plants won’t have the food they need.

Fertilizing helps recycle the nutrients that subsequent crops will need to produce high yields. It is nothing more or less than completing this natural growth cycle.

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