Fertilizer Fundamentals
What is fertilizer?
Simply put, fertilizer combines the nutrients that plants need to grow – potassium, nitrogen, phosphorus, and sulphur– 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 nutrients that next year’s crop will require.
Are there chemicals in fertilizer?
The four main ingredients in fertilizer: nitrogen, potassium, phosphorus and sulphur come from nature. They are not man-made. Fertilizer manufacturers 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?
Farmers use fertilizer to replenish the nutrients drawn from the soil, which plants need to grow. When a crop goes to market, so too does the potassium, phosphorus, and nitrogen it has absorbed from the soil. When farmers fertilize, they put back into the soil the nutrients their next crop will require.
While the same nutrients in fertilizer are naturally found in soil, they are not present in a sufficient supply for today’s high-yield farming. It can take years – even decades – for soil to rebuild the necessary nutrients essential to nurture a good crop.
Where does phosphorus come from?
Phosphorus used in fertilizer comes from the fossilized remains of ancient marine life found in rock deposits. 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 and is involved in seed germination to ensure plants use water efficiently. Phosphorus 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. Potassium is mined from these deposits.
Where does nitrogen come from?
The air all around us contains nitrogen. In fact, nitrogen makes up about 78 percent of the atmosphere. Fertilizer producers combine nitrogen with natural gas to change it into a form that plants can use.
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 and Food
What role do fertilizers play in feeding a growing world population?
Fertilizers play a 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 the use of commercial fertilizers.
If we are to meet future food demands, we will need to double our current levels of production. We can’t do that without fertilizers. Continuing to make better and more efficient use of fertilizer will help us feed the growing population.
Are organic foods better because they are grown without fertilizer?
Most organic growers use fertilizer too. It is 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 custom combinations possible with commercial fertilizers. Typically, compared to a farm using conventional fertilizer, organic crops produce one-third to one-half less yield. 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 is easy to over or under fertilize in this type of farming.
There is no concrete evidence to suggest organically grown food is better than food grown with conventional fertilizer. The three main ingredients used in fertilizer – nitrogen, potassium, phosphorus and sulphur – are found naturally in the soil and are required by all forms of life.
Fertilizer and the Environment
Is fertilizer harmful to the environment?
Commercial fertilizer has become an indispensable tool in today’s high-yield farming. It requires careful application and use to protect our environment. Fortunately, advances in agricultural techniques are enabling farmers to apply soil nutrients with pinpoint accuracy, minimizing or avoiding any damage to soil, water, and air.
New soil sampling, use of starter fertilizers, and better timing and placement of nutrients mean producers are producing their crops more efficiently. For example, farmers today are producing one-third more corn for each pound of nitrogen they apply, compared to 20 years ago.
Wouldn’t it be better for the environment to use less fertilizer?
By adopting nutrient stewardship practices, such as 4R Nutrient Stewardship, farmers contribute to the preservation of natural ecosystems by growing more on less land. As a result of advances in agricultural practices, farmers have been able to use fertilizer more efficiently.
It is important to maintain nutrient levels in the soil, for the overall health and longevity of a crop. An insufficient supply also reduces plants ability to withstand harsh weather, disease, and other stresses. Plants require adequate nutrients to 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.
Fertilizer and Soil
If there are already nutrients in the soil, why add more?
When farmers use fertilizer, they are replacing what has been absorbed by plants. Each growing season, crops take all the potassium, nitrogen, phosphorus and sulphur they need from the earth. 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 completing the ongoing cycle. This recycling of nutrients ensures that subsequent crops get what they need to grow.
While the same nutrients in fertilizer are naturally found in soil, they are not present in a sufficient supply for today’s high-yield farming. It can take years – even decades – for soil to rebuild the necessary nutrients essential to nurture a good crop.
Are we using more fertilizer, since yields are increasing?
We’ve made great strides in using fertilizer more efficiently and effectively. 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 using the principles of 4R Nutrient Stewardship (Right Source @ Right Rate, Right Time, Right Place®). These changes have enabled farmers to produce three times the yield using roughly the same number of acres of farmland as they did in 1960.
Would it be better to err on the side of under-fertilizing?
Today, farmers are producing higher yields using less fertilizer. Soils do not naturally contain the nutrients necessary to keep pace with growing world demand for food.
Following methods of 4R Nutrient Stewardship, which requires a farmer to test their soil to determine its exact nutrient requirements, allows them to apply only what the crop needs.
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 do not replace the nitrogen, potassium, phosphorus and sulphur this year’s crop has used to grow, next year’s plants will not 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.
Nutrient Stewardship – For Homeowner
Right Source
What type of fertilizer should I buy?
To make sure you’re buying the right fertilizer for your lawn; review your options at your local lawn and garden centre by reading the bag or asking someone who works there. You can also get your soil tested by a professional or with a home kit, available at most garden centres. Soil testing is the only way to assess the soil’s nutrient status.
A starter fertilizer contains more phosphorus to stimulate new root growth while a fall fertilizer helps to repair summer damage and build strong roots that protect the lawn for winter. All other fertilizers feed evenly for a thick, healthy green lawn.
Can I store unused fertilizer for use next year?
Yes, unused fertilizer can be stored. Keep any leftover fertilizer sealed in its original container in a dry place for use next season. If moisture gets in, you may have lumping of the fertilizer, so be sure to break up any clumps before placing in the spreader.
What are the three numbers on the fertilizer bag and what do they mean?
The three numbers on the bag (such as 10-0-5) indicate the ratio of three key nutrients included in all fertilizers: nitrogen, phosphorus, and potassium, always listed in this order. Meaning, if a bag reads 21-4-3 it contains 21 percent nitrogen, 4 percent phosphorus, and 3 percent potassium.
Nitrogen: Boosts growth and green colour.
Phosphorus: Feeds seedlings and stimulates new root growth.
Potassium: Provides all around vigour and health while strengthening for resistance to disease and stress.
What’s the difference between conventional fertilizers and organic fertilizers?
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 lawns. In this way, homeowners can feed their lawns with the most effective and efficient blend of potassium, phosphorus, and nitrogen to achieve the best results.
Organic fertilizer is made from different ingredients, such as livestock manure. These natural fertilizers do not provide nutrients in the fine-tuned combinations possible with commercial fertilizers. For example, using enough manure to provide an adequate supply of nitrogen could mean adding four to five times more phosphorus than what plants and lawns need. So, it’s easy to over or under fertilize.
What’s most important is that your plants and lawns can not tell the difference between conventional and organic fertilizers.
Right Rate
Do I have to apply fertilizer using a special spreader? Can I just use my hand?
Properly maintained and calibrated spreaders are designed to deliver an accurate amount of fertilizer evenly across the entire lawn. Uneven application can cause variations in lawn colour and potential burning if over-applied. Never spread fertilizer by hand.
If storage space is an issue, consider a handheld model for smaller lawns.
And don’t be intimidated by your spreader. All the steps for proper application are outlined on your fertilizer product bag.
What setting should I use for my spreader?
The fertilizer product label will tell you which setting to use.
How much fertilizer do I need?
First, you need to know the size of your lawn to know how much fertilizer is required for an application. Multiply your property’s length by its width, and then subtract the area of your house and any hard surfaces like driveways, patios or decks.
Here is a simple tip to help you visualize your lawn area: Picture a full tennis court with a fence around it. The area inside that fence is about 800 m2.
Once you know the size of your lawn, you’ll be able to choose the right amount of fertilizer to apply – the coverage area is outlined on the fertilizer product bag.
I just applied lawn fertilizer. Do I need to water the lawn right away?
It depends on the type of fertilizer you used for your lawn. Be sure to read the bag for application and watering instructions.
Dry fertilizers are taken up by the plant within 24 hours and act as a slow release – feeding the lawn slowly and evenly over a six to eight-week period with no watering required. Other fertilizers require a light watering following application.
Right Time
When should I apply fertilizer?
Feed your lawn every other month beginning in April. A lawn fed three to four times a year develops a deep root system to resist heat, drought, and wear. It also develops thick green top growth to naturally resist weeds, disease, and insects.
Why is it necessary to fertilize my lawn in the fall?
A thick and healthy lawn requires a strong root system. As the root system of the grass plant grows most vigorously in fall, feeding your lawn with an application of fertilizer in fall helps promote root growth. At the same time, fertilizing your lawn in the fall will prepare your green space for a long winter and help it recover in the spring.
How much fertilizer do I need?
First, you need to know the size of your lawn to know how much fertilizer is required for an application. Multiply your property’s length by its width, and then subtract the area of your house and any hard surfaces like driveways, patios or decks.
Here is a simple tip to help you visualize your lawn area: Picture a full tennis court with a fence around it. The area inside that fence is about 800 m2.
Once you know the size of your lawn, you’ll be able to choose the right amount of fertilizer to apply – the coverage area is outlined on the fertilizer product bag.
Is it okay to apply fertilizer during the hot summer months?
Do not apply fertilizer when the temperature is above 30 °C. Fertilizing in very hot and dry conditions can burn your lawn.
I am planning to de-thatch my lawn. Should I apply fertilizer before or after I de-thatch?
Apply fertilizer after you de-thatch.
I am planning to reseed my lawn. When should I apply fertilizer?
Apply a starter fertilizer after you seed. Starter fertilizers promote root growth, which will help new grass establish itself quickly.
Right Place
I just laid sod. Should I fertilize it?
Apply a starter fertilizer after you sod. Starter fertilizers promote root growth, which will help new grass establish itself quickly.
Do I use the same fertilizer for my garden?
No as different plants require different levels of nutrients. Choose a garden fertilizer or plant food and read the label to make your selection depending on the type of flower, shrub, or vegetable.
Is fertilizer safe for my pets and kids?
Fertilizer particles do not pose a safety risk to you, your kids, or your pets. To avoid picking up any fertilizer particles on footwear or feet, we recommend waiting 24 hours if children and pets want to play on the lawn.
My property backs onto a pond. Is it safe for me to fertilize my grass?
Use a low phosphorus or phosphorus-free fertilizer, but if you suspect a phosphorus deficiency is limiting the growth of your grass, take a soil test before buying a fertilizer containing phosphorus. Leave a buffer zone when applying to keep the fertilizer out of the water because phosphorus can promote algae growth.
Applying fertilizer properly will help to ensure fertilizer stays where it belongs – on the grass.
Is fertilizer bad for the environment?
No, when used correctly, fertilizer plays an important role in helping healthy, green grass grow, and healthy turf has many environmental benefits. Healthy green space has a dramatic cooling effect compared to hard surfaces, acts as a water filtration system, produces lots of oxygen, reduces water run-off and provides a soft, safe outdoor space for people and pets to rest and play. Dense grass also helps trap significant amounts of dust and dirt particles; an acre of grass will absorb hundreds of kilograms of sulphur dioxide per year.
I am planning to reseed my lawn. When should I apply fertilizer?
Apply a starter fertilizer after you seed. Starter fertilizers promote root growth, which will help new grass establish itself quickly.