All of the nutrients that are essential to plant life and growth are present in the soil or are floating in the air, this is not the case with hydroponics. Plants do not have access to nutrients. Hydroponic plants are at the whim of their growers and rely on them for every single nutrient they need. For these reasons, it is important to replenish and replace those elements that are not accessible to plants.
To make plants grow, what you need to do is supply the elements that the plants need in readily available forms. That is the goal of fertilizer. For this, you need to use liquid nutrients like:
When it comes to fertilizing, more does not mean better. It is possible to overfeed your plants. Too much fertilizer can damage, burn, and maybe even kill your plants. Before applying any fertilizer, it’s a good idea to have your soil tested so you can select the type and formula that suits your plants’ needs. In return, plants will reward you with bigger flowers, bigger leaves, and bigger fruits and vegetables.
What Is In Fertilizers?
There are six primary nutrients that plants require. Plants get the first three—carbon, hydrogen, and oxygen—from air and water. The other three that plants require are nitrogen, phosphorus, and potassium. In nature, the nitrogen, phosphorous and potassium often come from the decay of plants that have died. In the case of nitrogen, the recycling of nitrogen from the dead to living plants is often the only source of nitrogen in the soil.
The numbers on a bag of fertilizer tell you the percentages of available nitrogen, phosphorus, and potassium found in the bag. So 12-8-10 fertilizer has 12-percent nitrogen, 8-percent phosphorous and 10-percent potassium. In a 100-pound bag, therefore, 12 pounds is nitrogen, 8 pounds is phosphorous and 10 pounds is potassium. The other 70 pounds is known as ballast and has no value to the plants.
How Do The Elements Help The Plants?
Nitrogen helps plants make the proteins they need to produce new tissues. In nature, nitrogen is often in short supply so plants have evolved to take up as much nitrogen as possible, even if it means not taking up other necessary elements. If too much nitrogen is available, the plant may grow abundant foliage but not produce fruit or flowers. Growth may actually be stunted because the plant isn’t absorbing enough of the other elements it needs.
Phosphorus stimulates root growth, helps the plant set buds and flowers, improves vitality and increases seed size. It does this by helping transfer energy from one part of the plant to another. To absorb phosphorus, most plants require a soil pH of 6.5 to 6.8. Organic matter and the activity of soil organisms also increase the availability of phosphorus.
Potassium improves the overall vigor of the plant. It helps the plants make carbohydrates and provides disease resistance. It also helps regulate metabolic activities.
There are three additional nutrients that plants need, but in much smaller amounts:
Calcium is used by plants in cell membranes, at their growing points and to neutralize toxic materials. In addition, calcium improves soil structure and helps bind organic and inorganic particles together.
Magnesium is the only metallic component of chlorophyll. Without it, plants can’t process sunlight.
Sulfur is a component of many proteins.
Finally, there are eight elements that plants need in tiny amounts. These are called micronutrients and include boron, copper, and iron. Healthy soil that is high in organic matter usually contains adequate amounts of each of these micronutrients. You can find all of these elements in products that specialize in nutrient solutions like Complete Hydroponics.
How Does pH Play a Role?
Some nutrients cannot be absorbed by plants if the water pH is too high or too low. For most plants, water pH should be between 6.0 and 7.0. So it is important to test your water and measure the pH. You can send a sample to a lab or buy a home kit and do it yourself. Keep in mind that it’s best to raise or lower soil pH slowly over time. Dramatic adjustments can result in the opposite extreme, which may be worse than what you started with.