Growing Greenhouse Crops With the Latest Plant Nutrient Tools

The year 2022 has shown us that traditional practices and solutions can be turned on their head. Increasing costs of everything, supply chain problems and a war in Europe combined to increase operating costs for almost everyone. From electricity to diesel fuel to fertilizers, producers have faced headwinds.

For controlled environment agriculture (CEA), whether it is a ripening house, a greenhouse or an indoor vertical farm, plant nutrition and plant health are at the heart of the problem. Nutrient uptake efficiency, plant root mass and vigor, disease resistance, and yield are all areas where improvements can greatly impact your bottom line. Whether it’s cutting costs – less fertilizer – or increasing yields, this economy makes it more important than ever. Here’s a snapshot of where efforts are focused for 2023.

Tiny bubbles in your water

You may not have heard of nanobubbles, but they have been around for a long time. Found in the ocean, they are now used in horticulture, aquaponics, reversing lake eutrophication, mining, and many other fields.

Nanobubbles are essentially tiny little bubbles. As the name suggests, they are measured on the nanoscale, typically 100 nanometers in diameter, or about 2,500 times smaller than a grain of table salt. Remember that a nanometer is one billionth of a meter.

These super small bubbles of gas, in this case oxygen, stay suspended in solution instead of rising to the surface like a normal bubble because they are neutrally buoyant.

The CEA community uses nanobubbles for several reasons. Research and results indicate increased oxygen availability for plant roots, promotion of an aerobic environment in the rhizosphere, suppression of pathogens pythium And Fusariumand increased nutrient availability and absorption.

In other words, growers using nanobubbles report reduced fertilizer usage, improved plant health, more plant root mass, and higher yields. Unlike ozone or other treatments, nanobubbles cannot be overdosed and harm plants.

This relatively new technology also shows other advantages. Due to the oxidizing properties of nanobubbles, biofilm reduction in irrigation and fertigation systems is significant.

Nanobubbles and organic nutrient sources work well together with less clogging, less system maintenance and better nutrient uptake. It works well with hydroponic systems, especially when the temperature is rising and traditional systems struggle to keep dissolved oxygen (DO) high in warmer water.

The integration of nanobubbles into an existing operation is fully scalable. Davey Rock is the Moleaer Business Development Manager for the Midwest region. He first became interested in nanobubbles when he saw the benefits in his own grow operation. Now he is working to make this ability available to others.

“Any grower can benefit from nanobubble technology,” says Rock.

Nanobubbles can be integrated into any size operation with units that accommodate irrigation system configurations and water usage from a few hundred gallons per day to more than 100,000 gallons per day.

The return on investment can also be quick. Effects like higher yields, shorter cycle times, less line maintenance, and less use of fertilizers and fungicides add up like compound interest. While the answer to the specific time frame for an investment payback will always depend on the individual farm, Rock says many growers are seeing quantifiable benefits almost immediately and a return on investment in just a few months.

The benefits of micronutrients

Many minerals and compounds naturally occurring in soil are absent from modern soilless CEA. The nutrient that’s getting a lot of attention in the current environment is silicon.

While silicon is the second most abundant element in the earth’s crust, plants growing in soilless media in your CEA operation may be deficient in silicon. Pine bark, coir, peat and other mediums are low in silicon. Sand, perlite, rockwool and vermiculite do have silicon as part of their composition, but not in a plant-available form.

Since silicon is not essential for plants to grow, flower and reproduce, it was ignored in the development of our modern CEA systems. Erica Hernandez, CEA Technical Specialist at Griffin Greenhouse Supplies, advises growers on plant health issues. Today, she sees growers looking for benefits in terms of pest resistance and heat/drought tolerance. They are interested in silicon and in forms that are more easily degradable and available to plants than traditional potassium silicate.

When present, silicon is absorbed by the plant roots as silicic acid. This compound travels through the water-carrying vessels of plants, deposits, and then solidifies. Plants gain stronger cell walls, resulting in increased resistance to harmful fungal spores and insect attacks. Silicon also contributes to resistance to damage during shipping and heat tolerance.

More interest in biostimulants

Like a lack of minerals in soilless media, many of our beneficial biological factors are also lacking. Sterility — the absence of soil life — was part of the initial appeal of soilless growing media for reducing pathogens, but CEA operators may also lack beneficial soil life and lose the boost it can give to plant vigor. Healthier plants are more resilient to biotic and abiotic stress.

Hernandez says she and others are seeing an increasing interest from growers in biostimulants to reduce disease pressure and fertilizer use. These biostimulants come in two basic types: mycorrhizal and bacterial.

Mycorrhizal or fungal biostimulants can be used in transplantation. Mycorrhizae form symbiotic relationships with plants and increase their functioning root mass to increase nutrient uptake efficiency and water uptake.

Bacterial biostimulants add these beneficial bacteria, such as bacillus spp., back into the soil. These bacteria serve to break down nutrients into plant-available forms. B. subtilis is a rhizobacterium that has been shown to solubilize soil phosphorus, improve nitrogen fixation and suppress disease.

Bacterial biostimulants are more commonly used in cultures with shorter cycle times because they establish faster. Because of their extended establishment time, fungal biostimulants are often used in crops with longer crop rotations, including ornamentals, hemp, and cannabis, Hernandez says. Some products that are OMRI listed are now available for organic producers.

Growers looking to gain an edge may find combining multiple methods beneficial and a scalable solution to reduce operational costs and increase revenue from existing efforts. Lower fertilizer costs, less maintenance, and happier plants, whether for food or ornamental crops, can be a much-needed gain for 2023.