Soil Nutrients 101: The Role of Nitrogen, Phosphorus, Potassium in Fostering Green Grass

Is your lawn looking a little faded or lackluster? It’s probably in desperate need of some important nutrients.

While your soil can benefit from a myriad of minerals, nitrogen, phosphorus, potassium, magnesium, sulfur and calcium are considered “macronutrients”— and are needed in larger quantities than other “micronutrients” to promote healthy lawn growth.

However, the nutrients your lawn or plants needs the most are nitrogen, phosphorus and nitrogen. These are the most common ingredients found in store-bought fertilizers, but are easily confused and overused.

Let’s take a look at the importance of each soil nutrients and the role they play in creating gorgeous, green turf:

Soil nutrients

1. Nitrogen

There is more nitrogen in plants than any other element (besides carbon, hydrogen and oxygen), according to the University of Missouri.

You probably know a little about chlorophyll from your old science class; if you recall, it’s the part of a plant that’s responsible for giving it its green color. This chlorophyll takes in light energy and converts it into sugar (a process called photosynthesis) for your grass to “eat.” That chlorophyll is comprised of nitrogen!

This macronutrient is also found in your grass roots, where it helps with the uptake of water and other important nutrients from the soil.

If you leave with any knowledge of this nutrient, let it be this: nitrogen is apart of the compounds that control plant growth. That’s why lawn’s with excess nitrogen grow like crazy; they experience such high rates of photosynthesis that they just keep growing and growing. Nitrogen however only promotes top growth or what you seen above ground so excessive nitrogen actually harms the plant or turf because it isn’t feeding the roots which the plants need to sustain themselves. Our next nutrient contributes to growth as well: phosphorus.

2. Phosphorus

Phosphorus is responsible for the regulation of protein synthesis, and works hand-in-hand with nitrogen to foster lively plant growth. This important macronutrient helps your grass to store minerals and energy, as well as to transfer it to other parts of the plant to help it repair and regrow— like when you trim your grass and your blades needs to suck energy upwards to heal the “wound.”

Phosphorus does a lot for your turf’s root systems: helping them to develop properly and mature. This helps to increase your turf’s winter hardiness and resilience, as well as its ability to fight disease and defend against insect damage or sweltering, dry heat.

The nice thing is, it’s hard for your grass to receive too much of this nutrient, as it’s difficult for your plants absorb it in the first place. While it can be easy to over-fertilize with other minerals, bone meal or phosphorus-high compost can usually be applied without strict measurement.

Soil nutrients

3. Potassium

Potassium is associated with the movement of water, nutrients and carbohydrates in plant tissue, according to the University of Minnesota. The mineral helps to regulate the opening and closing of this thing called the stoma, which lets water vapor, oxygen and carbon dioxide in.

Oftentimes, grass that looks scorched or curled at the tips or is dry has a potassium deficiency. While moisture management products— like our Hydretain— can help your plants collect water, potassium is needed to help uptake the H20 through your grass roots and allow it to be absorbed into the plant.

It’s also an important player in enzyme activation, which affects protein, starch and adenosine triphosphate (ATP) production. What does all that mean? Basically, it helps with photosynthesis!

Are you noticing a theme here in the big three nutrients? They all aid in your grass’ ability to absorb and distribute nutrients.

Other Secondary Soil Macronutrients

We covered the big three macronutrients, found in most soil fertilizers. However, there are three other “secondary” minerals required in smaller amounts, that still play important roles in fostering lush landscapes:

  • Magnesium. Without this important soil nutrient, the chlorophyll in your grass cannot capture sun energy needed for photosynthesis. It’s the central atom in the chlorophyll molecule, so while it’s not needed in as high of quantities as nitrogen, phosphorus or potassium, it’s still kind of a big deal!
  • Sulfur. This macronutrient helps form important enzymes and assists in the formation of plant proteins, a key element in amino acids. Ninety percent of the sulfur absorbed by your grass helps your plant’s building blocks, but it can also assist in metabolizing nitrogen (the most important nutrient!) and with chlorophyll formation.
  • Calcium. Calcium pectate holds together the cell walls of your grass. Without it, new plant tissues, like shoot/root tips and young leaves, can't properly form. Think of calcium are a healing mineral to allow your turf to recover from stressful mows or damage.

Which Soil Minerals Are You Lacking?

The only true way to see what your dirt needs is to measure your mineral levels with a professional soil test.

This soil test will reveal deficiencies or over accumulation of soil nutrients, including your pH levels, so you can apply a nourishing fertilizer or compost.

Let our experts test your soil and recommend the right mineral-medley for your lawn, specifically. We can whip the exact ratio you need and treat your landscape properly.

For those who want to tackle the job yourself, download our free ebook, the Ultimate Guide to Fertilization. It can help you to choose the best product, understand how to spread it and more.

Guide to Fertilization

Topics: Gardening, Lawn Care