Capturing more nutrients with mycorrhizae

Greenhouse Management: What problems do growers face that can be solved with mycorrhizae?

Blair Busenbark: Growers face three major problems that can be solved with mycorrhizae: fertilizer shortages and increased costs, water shortages and increased costs, and labor shortages and increased costs.

GM: What is contributing to increased fertilizer costs?

BB: Growers have faced fertilizer cost increases due to the Russian invasion of Ukraine. So much fertilizer was mined out of those countries. Anything mined is a finite resource right now, so it’s causing disruption and raising prices. The war is not ending anytime soon, and even when it does end, the disruptions will continue for some time. 

GM: How does mycorrhizae help with nutrient uptake?

BB: Mycorrhizae expands the root absorptive area of a plant, making it better able to pull in more of the nutrients and the water in the rhizosphere than the roots or root hairs on their own. Whether it’s a controlled-release fertilizer, a liquid fertilizer or an organic feed, the mycorrhizae is better able to capture the nutrients than the plant alone. As fertilizer prices increase, that benefit becomes even more valuable.

The mycorrhizae can also store nutrients in times of excess and then release it when it needs it, and basically the plant controls that relationship. So when the plant says ‘I need more phosphorus,’ the mycorrhizae can pull from the stores or it can go out into the soil and source that phosphorus, bring it into the plant and make it available.

GM: How does mycorrhizae help with water dependency?

BB: Whether growers pull it from a natural source or they pay for it, water is getting more expensive. Irrigating inefficiently is costing much more than it used to, and many growers can’t pump enough water for their needs. Mycorrhizae can give plants a buffer before they wilt. When plants wilt, it’s a sign of stress. When they’re stressed, they’re vulnerable to opportunistic pathogens or insects. If they can go 24, 36, 48 hours longer before they wilt, that gives the growers that buffer they need to be able to access the water and be able to apply that water to the plant. Ultimately, having to water the plants less over the summer reduces their costs, both with labor and energy associated with irrigation.

GM: How can mycorrhizae help with the labor issue faced by growers?

BB: Whether it’s automation or better utilization of human labor, mycorrhizae can play a role in using the labor you have more effectively. Plants, liners or plugs grown with mycorrhizae are fuller and more uniform. That means production can run more smoothly, as growers can apply one procedure to an entire block of plants instead of needing to provide extra touches or special care.