Plant Nutrition In Hydroponics
Hydroponics cultivation is considered to be superior to conventional cultivation because of the numerous advantages it offers. Both commercial scale production and small scale crop cultivation using hydroponics techniques have proved to be advantageous in many respects. One of the advantages of hydroponics is its simplicity. However, what is essentially a fairly simple, straight forward technique may at times seem complicated, especially to the newly initiated. This is particularly so regarding issues such as plant nutrition in hydroponics. Given the plethora of tonics, additives, growth enhancers and other concoctions, that promise accelerated growth, bigger yields and so on, one of the basic aspects of hydroponics viz. plant nutrition may seem frustratingly complicated. It isn’t though.
Nutrient Formulations
All plants, whether they are grown in soil or with hydroponics require a balance of nitrogen, phosphorous and potassium (N-P-K) and trace elements to grow properly. These nutrients are available to plants in soil in small amounts, but over time they get depleted and need to be supplied separately to make up the deficit. In hydroponics, it is all the more important to ensure that plants get the right nutrients in the right amounts.
Hydroponics formulations are structured for specific stages of plant life cycle. A plant’s nutritional requirements vary 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 in development of leaves and stems. Deficiency of 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 ratio of nitrogen, the plant requires less nitrogen more phosphorus and potassium.
Using good quality formulations that contain the vital elements for plant growth should be the first consideration in providing for plant nutrition in hydroponics.
Keep it Simple
Following a good nutrient regime and keeping it simple will go a long way to ensure adequate uptake of all the essential nutrients. It is advisable not to use too many formulations 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.
Growth Enhancers, Boosters and Fortifiers
Certain commercial products have been developed that can stimulate faster nutrient uptake and speed up stem and leaf growth. Many of these products are best left to the advanced and experienced growers. Novice hydroponics enthusiasts should approach such products like growth boosters with caution. Also, there are several products available in the market that claim to work as bloom fortifiers. These formulations act to stimulate flowering and increase essential oils in plants. While selecting a bloom fortifier, the best thing to do is to select one with an NPK ratio of 0-50-30. Such fortifiers have no nitrogen and are rich in Phosphorus and Potassium. These essential minerals stimulate the formation of super blooms.
Organic Formulations
Organic gardening has caught on in recent years and the hydroponics industry has sought to integrate organic growing practices in hydroponics cultivation. Several organic formulations 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 does not require shaking prior to use as any sediment is likely to clog lines and pumps. Also take note that organic formulations meant for soil cultivated plants are not suitable for use in hydroponics as these will clog the pumps and lines resulting in burning of plants.
Other Considerations
Plants need to have fresh nutrients available for healthy growth. Ensuring regular reservoir changes every week is essential. pH and electro conductivity should be checked while mixing the nutrient solution. While the electro conductivity reading will help determine the amount of dissolved nutrients, the pH reading will help in maintaining pH values at levels that will enable plants to absorb the nutrients.
Leaching or rinsing should be carried out one week prior to harvest. This can be done using regular tap water through the system to wash out excess salts that remain in the growing medium.
Keeping a gardening journal will help in avoiding mistakes and establish pointers to the right course of action. Making journal entries regularly will, in course of time, help build up a veritable treasure trove of valuable information on various aspects of nutrition, pH, EC etc.
Appendix
Plants require two types of nutrients for healthy growth- macro-nutrients and micro-nutrients. Plants use macro-nutrients in large amounts while micro-nutrients are required in trace amounts. Following is a list of Macro and Micro- Nutrients and their functional importance in plant growth:
Macro-nutrients and their role plant growth
o Carbon – Formation of organic compounds
o Oxygen- Release of energy from sugar
o Hydrogen- Water formation
o Nitrogen- Chlorophyll, amino acids, proteins synthesis
o Phosphorus- Vital for photosynthesis and growth
o Potassium- Enzyme activity, Sugar and starch formation
o Calcium- Cell growth and division, component of cell wall
o Magnesium-Component of chlorophyll, enzyme activation
o Sulfur- Formation of amino acids and proteins
Micro- nutrients and their role in plant growth
o Boron – Vital for reproduction
o Chlorine – Helps root growth
o Copper- Enzyme activation
o Iron- Used in Photosynthesis
o Manganese- Component of chlorophyll, Enzyme activation
o Sodium- Vital for water movement
o Zinc- Component of enzymes and auxins
o Molybdenum- Nitrogen Fixation
o Nickel- Nitrogen Liberation
o Cobalt- Nitrogen Fixation
o Silicon- Cell wall toughness