Major Nutrients Needed by Lawn Grass
Monday, June 22nd, 2009
Making sure your lawn receives the proper nutrients is an important part of lawn care.
A key component of lawn care is providing the lawn with the nutrients it needs to grow. Each nutrient is involved in different plant processes. Nutrients are loosely grouped into two categories: Macronutrients and micronutrients. The nutrients listed under Macronutrients are almost always in lawn fertilizers. Potassium, calcium, magnesium and sulfur are sometimes categorized as macronutrients, and other times as micro-nutrients. Each has its specific function in plant growth and development.
Macronutrients
- Nitrogen
- Phosphorous
- Potassium
Micronutrients
- Calcium
- Magnesium
- Sulfur
- Iron
- Manganese
- Copper
- Zinc
- Boron
Lawn Fertilizer Analysis
Most lawn fertilizers contain the macronutrients, or what you could call “the big three:” Nitrogen (N), Phosphorous (P), and Potassium (K). The fertilizer bags have their N-P-K analysis, or numbers that tell consumers how much of each nutrients is in the fertilizer, by percentage. This can also tell you how many pounds of active ingredient are in each type of fertilizer. For example, a 10-10-10 fertilizer has the same percentage of each ingredient. 100 lbs of the fertilizer would have 10 lbs of each active ingredient. Here’s what each of the “big three” do for plants:
Nitrogen: The basis of all protein and DNA. Used mostly for growth. Nitrogen application is said to “green up the grass” because it is incorporated into the leaf tissue.
Phosphorous: This nutrient plays an integral part in photosynthesis, energy transfer and flower/fruit growth. Plants without enough phosphorous do not produce many fruits, and their seeds can be deformed or not fully formed.
Potassium: Many processes within the plant use potassium. Sugar movement, cell division, root development and water retention all require potassium.
Micronutrients are just as Important
Even though most fertilizers contain only Nitrogen, Phosphorous and Potassium, the micronutrients are just as important for healthy plant growth, and lawn grass will show the affects of an imbalance, or too little of any of these nutrients.
Calcium: Plants without enough calcium have thick, woody stems and poor root development. Lack of calcium can give the grass a yellowish hue. The ratio of calcium to magnesium must be 7:1 for proper plant growth.
Magnesium: Chlorophyll is partially made of magnesium, and needs this nutrient to function. Too much Potassium in the soil can prevent magnesium from being present in the soil in a form that is available to plants.
Sulfur: proteins have sulfur components in them. Peppers, onions, cherries and plums need plenty of sulfur to bloom and produce good fruit set. Many lawn grass fertilizers have a sulfur component.
Iron: Iron uptake is affected by the amount and form of manganese. Iron can bond tightly with soil particles. Addition of a light layer of compost raked into the grass can re-introduce iron into lawns where it is deficient.
Manganese: Plants require manganese to oxidize enzymes. Acid soils (lower pH) tend to make more manganese available than alkaline (high pH) soils.
Copper: Copper is a catalyst for specific enzymes within plants. Many plant growth processes rely on sufficient copper.
Zinc: Protein and starch building processes require zinc. Too much Phosphorous in a lawn can bind up Zinc and make it unavailable to plants.
Boron: Flowering, fruit and seed formation are affected by boron.
Identifying Specific Lawn Nutrient Needs
Before applying fertilizer to the lawn, it is always a good idea to have a soil test done. You can pick up soil test boxes at your local cooperative extension office, along with instructions about how to collect a representative sample and prepare it for testing. Fertilizer is expensive, and over-use of nutrients can cause pollution. Getting a soil test will ensure that you are supplying your lawn with the right nutrients in the right amounts for healthy growth.
