Plant Nutrition

Hydroponics cultivation is considered to be superior to conventional cultivation because of the many advantages it offers. For both commercial and small scale crop cultivation, hydroponics techniques have proved to have advantages in many areas. One of the advantages hydroponics offers is its simplicity. However, what is a fairly simple and straight forward technique can seem complicated at times, especially to beginners. This is especially true when it comes to the issue of plant nutrition. Given the countless number of tonics, additives, growth enhancers, accelerators, and other concoctions that promise accelerated growth, bigger yields and so on, this basic aspect of hydroponics can seem frustratingly complicated. The good news is that with a little reading and hands-on experience, it isn’t. Following a good nutrient schedule and keeping it simple will go a long way, ensuring proper uptake of all essential nutrients. It is best not to use too many products as it may be very difficult to trace the exact cause of the problem if there are many additives and supplements in the nutrient mix.

Nutrient Formulations

All plants, whether they are grown in soil or with hydroponics require a balance of nitrogen, phosphorous, potassium (N-P-K), and other macro and/or micro (trace) elements to grow properly. These nutrients are available to plants in soil in small unknown amounts, but over time they get depleted and need to be supplied separately to make up for the deficiency. In hydroponics, it is all the more important to be sure that plants are getting the right nutrients in the right amounts at the right times. Hydroponic nutrient formulas are structured for specific stages of a plants life cycle. A plant’s nutritional requirements change according to the stages of its life cycle. When plants are in the vegetative stage, they require greater amounts of nitrogen, which is the key element for the development of leaves and stems. A deficiency in nitrogen during the growth period leads to stunted growth with yellowing of leaves. This is the most commonly seen deficiency in plants. During the flowering cycle the plant requires less nitrogen, but more phosphorus and potassium. Using good quality nutrients that contain the vital elements for plant growth should be the first consideration in providing plant nutrition in hydroponics.

Growth Enhancers, Boosters and Fortifiers

Many products have been developed that can stimulate faster nutrient uptake and speed up stem, leaf, and flower/fruit growth. Many of these products are best left to the advanced and experienced growers. Novice growers should approach such products with caution. Several products available on the market work specifically as bloom fortifiers or enhancers. These formulations act to stimulate flowering and increase essential oils in plants. While selecting a bloom fortifier, the best thing to remember is to select one with a proper NPK ratio. Such fortifiers will generally have no nitrogen and are rich in phosphorus and potassium. These essential minerals stimulate the formation of super blooms.

Organic Formulations

Organic gardening has become popular in recent years and the hydroponics industry has sought to integrate organic growing practices into hydroponic cultivation. Several organic products have been successfully developed, tested and marketed. Organic formulas for use in hydroponics should be soluble, stand-alone products that leave no sediment in the container. Make sure the organic formula can be used in hydroponics and does not require shaking prior to use. Any sediment in the formula will likely clog your tubing and water pumps. Organic formulas meant for soil cultivated plants are not suitable for use in hydroponics due to issues with clogged equipment, which will result in damage to your plants.

Other Considerations

Plants need to have fresh nutrients available for healthy growth. It is important to do regular reservoir changes every week. pH and electro conductivity (ppm) should be checked while mixing your nutrient solution. While the ppm reading will help determine the amount of dissolved nutrients, the pH reading will help in maintaining acid and alkalinity levels that will enable plants to absorb the nutrients. Flushing or rinsing should be carried out at least one to two weeks prior to harvest. This can be done using regular water or a flushing solution in your system to wash out excess salts that remain in the growing medium. Many people like to keep a gardening journal which will help in avoiding repeat mistakes and establish pointers to the right course of action. Overtime, making journal entries regularly will help build up a wealth of valuable information on various aspects of nutrition, pH, EC, etc., that are specific to you and your garden.

Macro and Micro nutrients

Macro-nutrients and their role in plant growth

• Carbon- Formation of organic compounds
• Oxygen- Release of energy from sugar
• Hydrogen- Water formation
• Nitrogen- Chlorophyll, amino acids, proteins synthesis
• Phosphorus- Vital for photosynthesis and growth
• Potassium- Enzyme activity, Sugar and starch formation
• Calcium- Cell growth and division, component of cell wall
• Magnesium-Component of chlorophyll, enzyme activation
• Sulfur- Formation of amino acids and proteins

Micro- nutrients and their role in plant growth

• Boron – Vital for reproduction
• Chlorine – Helps root growth
• Copper- Enzyme activation
• Iron- Used in Photosynthesis
• Manganese- Component of chlorophyll, Enzyme activation
• Sodium- Vital for water movement
• Zinc- Component of enzymes and auxins
• Molybdenum- Nitrogen Fixation
• Nickel- Nitrogen Liberation
• Cobalt- Nitrogen Fixation
• Silicon- Cell wall toughness