Plant nutrition is an interesting subject matter. For millions of years, plants thrived without our help, but now that we have begun raising our own plants, the issue of nutrition has come up and has been debated by experts in the industry. So, what do you need to know about plant nutrition and could changing the way you are feeding your plants make them even healthier? This guide will discuss the current school of thought on plant nutrition and open the door on what has been shown to keep plants the healthiest.
There are four categories of nutrients that plants require. All of these nutrients are essential to healthy growth and continued life, and the categories come from the type of nutrients or the method by which they are consumed by the plant. For example:
Primary Macro-nutrients: nitrogen, phosphorus and potassium
Secondary Macro-nutrients: calcium, sulfur and magnesium
Trace Minerals: boron, manganese, iron, zinc, copper, nickel, molybdenum and chlorine
Air Macro-nutrients: hydrogen, carbon, oxygen
As you can see, there are two ways that plants get their nutrients. Most of them come from the soil, (or another grow medium in the case of a specialized method like hydroponics) and the rest come from the air. All are vital to plant health. Most of the nutrients are absorbed through the roots of the plant, but the ones like nitrogen and oxygen are absorbed through the leaves.
What Happens When Plants Don’t Get Enough Nutrients?
If a plant doesn’t get enough nutrients, it is known as a nutrient deficiency, something that humans can also get if they don’t get all of the vitamins and minerals that they need. Plants can show all sorts of symptoms of nutrient deficiency: stunted growth, discoloration, deformity and death. Most of the time, it is nitrogen that plants aren’t getting enough of, but it usually takes several nutrient deficiencies to cause serious problems.
Nitrogen: Nitrogen is a part of the energy systems and amino acids inside the plant that forms its proteins. It is necessary for the process of chlorophyll photosynthesis and without it the plant will not be able to use sunshine as an energy source.
Phosphorus: A deficiency of this nutrient can make some plants show deformities. Corn is a good example of this. Phosphorus is vital for converting captured sunlight into a form of energy that the plant can use.
Potassium: Potassium is very important for plants because it boosts many of the enzyme actions inside the plant, and without it, plants are not able to reach their growth potential. Lack of potassium can affect size, shape, color, taste and many other features of the plant.
Calcium: Calcium is part of the material that makes up the plant cell wall, something that is vital to protecting the plant and keeping it strong. It also is a key factor in activating many of the plant’s enzyme systems.
Sulfur: Sulfur is vital to the process of photosynthesis; it also helps to protect the plant when the season turns cold. Without it, many plants are not able to survive winter conditions. Also, sulfur can affect taste in some plants with strong odors: onions for example.
Magnesium: Magnesium is required to capture the energy of the sun and use it for growth. It is also a factor in the process of photosynthesis and magnesium has the ability to move throughout the plant, from old tissue to younger tissue.
Boron: Boron improves seed set. It is also a vital component in cell walls, which help the plant keep its structure, even though it is in a small amount. However, boron does have the distinction of being a nutrient that can be toxic to the plant if too much is introduced into the soil.
Manganese: Manganese is important to the process of photosynthesis because it aids in chlorophyll synthesis, but some plants require more of this nutrient than others do, so you really have to know the plant that you are growing in order to know how much to give in artificial grow environments.
Iron: Plants that are suffering from an iron deficiency will often have paler leaves than healthy plants, and it is important that iron be balanced with other metals like copper and manganese. In some plants, like legumes, iron acts as a carrier for the oxygen that the plant needs.
Zinc: Since zinc is unable to move very easily, you will first notice a zinc deficiency by the wilting of younger leaves.
Copper: Copper has even more difficulty moving throughout the plant than zinc does, and in fact, is the least mobile of all seventeen of the plant nutrients. It is a catalyst for several different chemical reactions within the plant.
Nickel: Some of the fruit that trees bear and some plants in a nursery setting can have nickel deficiencies. You can tell if a plant has a nickel deficiency if the leaves have a small curl in them and if the plant has stunted growth.
Molybdenum: It is easy to see when a plant has a molybdenum deficiency. The first thing you will notice is stunted growth (if next to a healthy plant) and then the plant will turn a sickly, yellow color.
Chlorine: Chlorine helps both to break down the water that the plant receives, and to help the plant process sunlight. Also, chlorine is instrumental in the process of controlling the release of moisture so they can survive dry periods.
Hydrogen: Hydrogen is present both in the soil and in the air, and hydrogen has many jobs in the plant, not the least of which is helping with structure and photosynthesis.
Carbon: Carbon is the number one energy source that the plant uses. It is also necessary for the plant to build more tissues, so stunted growth, or no growth at all, can be a result of carbon deficiency.
Oxygen: Not only do plants give off oxygen so that we can breathe, they also acquire it from the carbon dioxide that they break down.