Maximum Yield USA May 2018 | Page 60

indoor vs. outdoor nutrients “When grow media systems have faster percolation, using a slow-release fertilizer can have nice Indoor vs. Outdoor Nutrients Again, the same nutrients are generally required to produce a healthy and productive plant, no matter if it is grown indoors or outdoors. Due to the nutrient-leaching aspect of most indoor hydroponic systems, you need to replenish your nutrient levels two to three times more frequently. This is a typical nutrient depletion estimate; it’s not specific to any single method or set-up. Recirculating indoor systems are different, however. As it’s normal to refresh the water reservoir and re-establish nutrient levels in these systems, this also impacts the frequency and amount of nutrients to add. If the nutrients applied to your crop are being recirculated by your grow system, then their removal will be primarily based on plant utilization and the requirement to flush the system. What is most certain is that nutrient levels will decrease much faster in non-recirculating hydroponic systems and so adding nutrients will need to happen more often. Most manufacturers provide recommendations regarding the application amounts and timing for their fertilizers. Some will give multiple recommendations based on different planting applications, such as planting into the ground, raised beds, or pots. However, because there is such a diversity of drainage and percolation rates for grow media, it’s difficult for a manufacturer to accurately anticipate exactly what you’re using and need as far as a schedule goes. Ultimately, the grower needs to know the percolation rate for their grow media. A key to selecting the right fertilizer for your crop is to match instructions found on that fertilizer with your growing set-up. When grow media systems have faster percolation, using a slow-release fertilizer can have nice benefits. Some of these slow-release fertilizers are made by coating the nutrient. 60 grow cycle A very thin layer of plastic film is impregnated with a release agent and then used to coat a granule of fertilizer. This then retards the release of that granule, allowing for a variety of release times following application. Most of these slow-feed fertilizers are released by adequate temperature and water. In grow media that are watered more frequently, this will cause the nutrients to be released faster, which is beneficial. Also, some nutrients change state during their exposure to soil or various grow media. Calcium, phosphorus, and magnesium precipitate more quickly than other nutrients. This means that they turn from their ion form (salts), which are plant available, into solids or other forms that are not plant available. If you have established a living soil or medium, one that is teaming with biological life, the microbe activity will work to convert the non-ionic form of nutrient back into that form where the plant can uptake it. Testing the nutrient levels of your leaf tissue, grow medium, or soil is the best way to discover whether the fertilizer or application rate you’ve been using is optimal for your crop. Testing nutrient levels in the soil or nutrient tank is great for staying on top of providing the proper nutrient levels as you go. There are many meters and test kits available to help you discover the rate of nutrient depletion. Plant tissue testing, on the other hand, will provide important information of the level of these nutrients that are getting into the plant. These two techniques are meant to work together to give the most complete picture of plant health and nutrition. The primary differences between indoor and outdoor nutrients are their ability to compensate for the differences in percolation rates of grow media or soil and the resulting changes in application timing. Knowing this will help the grower to get the maximum yield from their crop. For more information, click on the QR code.