Let me get started with a prediction: Within 4 years, prototype camera systems will be able to evaluate a crop canopy’s nutritional status, utilizing hyperspectral cameras that assess thin slivers of the visible spectrum, and change fertilizer injectors and irrigation systems practically instantly.
If that seems far-fetched, take into account that handheld Soil-Plant Analyses Development (SPAD) meters-that measure leaf greenness, quantifying differences invisible for the naked eye and providing a rough correlation with nitrogen content-have been readily available for years. Growers could be the ones who calibrate these camera systems-not the engineers who build them-so migrating to data-driven making decisions now will provide you a competitive advantage.
For the time being, this article provides insights in to the fertilization of solid root substrates (rockwool, coir, etc.) using inorganic salts, though some growers successfully use organic sources. Most of the concepts apply to all formulation types. Scheduling and fertilizer-application decisions start with effective monitoring.
What you should Monitor
Root substrates should be tested for pH and electrical conductivity (EC) a minimum of every fourteen days employing a non-destructive “pour-through” technique. Graph these results. You’ll learn the trends that develop over your crop’s growth stages. Also, occasionally track this data every couple of hours following a fertilization. You’ll be surprised how fast the plant takes up fertilizer within round the clock. Adjust fertilization accordingly to maintain your required pH and EC, based upon crop stage and your knowledge of the cultivar. The fertilization schedule will be different based on sunlight and temperature in a greenhouse or outdoor setting, and definitely will maintain more stability in controlled environments.
You are able to determine a powerful, data-based knowledge of your crop’s nutrient status by creating a graph that compares laboratory testing results for individual nutrient levels overlaid together with your routine pour-through tests. Substrate testing by an external lab is pricey, with tissue testing a lot more so. For cost effectiveness, track soil and cannabis nutrient recipe regularly for your first two crops in a new grow system, then annually next. Tissue and soil samples should be taken every fourteen days, minimum. Your end goal is to produce a “hospital chart” hanging near the crop for the entire team to make reference to, with actual measurements plotted over time and desired ranges clearly indicated. This can effectively facilitate consistent nutrition across crops and multiple growers, and then in multiple facilities.
Water-soluble fertilizers are best delivered using a fertilizer injector, which doses the correct proportion of a concentrate into hoses, dripper lines or sprinklers. Of course, injectors may also be used to fill a hydroponic or ebb-and-flood reservoir. These are water-driven, so don’t require electricity. Injectors should be sized based upon your anticipated flow rate: Exceeding an injector’s flow capacity causes it to get up, along with a sub-minimum rate brings about inaccurate dosing.
Larger, more expensive units measure the flow rate to dose most accurately, use a 15- to 20-year lifespan, and may be integrated into environmental control systems. They may also be integrated with pH and EC probes plumbed directly into the delivery pipes for monitoring, feedback and alarming.
Smaller devices could be mounted close to the crop or over a dolly for portability. Their lifespan could be a lot more than five years if shielded from direct sunlight and flushed when removed from use. Whether fixed or portable, it’s effective to have a bypass on or plumbed round the injector for applying domestic water without nutrients.
Some units use a fixed dosing ratio, while more versatile ones have adjustable settings. Electronic solenoids could be integrated for automating the device, if you have an irrigation controller. Additionally you can attach battery power timer to cwilkj water spigot that supplies the injector.
A great guideline for watering volume or duration: You can’t overwater containerized plants by using too much at the same time. When the substrate reaches container capacity, any added solution runs out the drainage holes. It is possible to only overwater by not allowing the substrate to dry properly between irrigation events.
Apply fertilizer solution until water pours out the base of the pot. This leachate should be a minimum of twenty percent of the items was applied. In the event you add less, fertilizer salts will accumulate within the pot. This can lead to root damage. Irrigating to some 20-percent leach fraction keeps a proper nutrient balance inside the substrate, making it possible for consistent availability and optimum nutritional status.