MSU experts tackle greenhouse efficiency

By Andi Anderson

Michigan State University (MSU) scientists, led by horticulture professor Tom Fernandez, are researching ways to improve water and nutrient efficiency in greenhouses and nurseries.

With support from Project GREEEN, MSU’s plant agriculture initiative, Fernandez has focused on strategies that help manage agricultural inputs like fertilizers and pesticides, reducing their impact on the environment.

Fernandez’s research addresses a common issue in greenhouses: overwatering. Containers used for plants allow excess water to drain easily, leading to significant runoff of nutrients and pesticides.

By adjusting irrigation to match a plant’s daily water needs, Fernandez has found that water usage can be reduced by 30%-80%, depending on the plant species. This approach conserves water and minimizes nutrient runoff from fertilizers like nitrates and phosphates.

In addition to nutrient management, Fernandez has studied how to reduce pesticide movement. Pesticides often land on non-target areas, such as groundcover or spaces between plants, where they can be washed away by overhead irrigation.

By applying less water and using micro-irrigation techniques, such as spray stakes that deliver water directly to individual containers, pesticide runoff can be significantly reduced.

Fernandez emphasizes the importance of timing when it comes to managing both nutrients and pesticides, stating that the longer these substances remain out of water systems, the more time there is for biological processes to neutralize them.

Expanding on his work, Fernandez has teamed up with Gemma Reguera from MSU’s College of Natural Science to study bioreactors—large tubs of woodchips that help filter out contaminants.

These bioreactors were designed to remove nitrates and phosphates from greenhouse water. Research showed that over 95% of nitrates and up to 87% of phosphates could be effectively removed by running water through these systems.

This innovative approach not only improves water quality but also provides a sustainable way to manage agricultural inputs, enhancing both the economic and environmental health of greenhouse and nursery operations.

The ongoing research continues to develop strategies that help farmers efficiently use resources while protecting the surrounding ecosystem.

Photo Credit: michigan-state-university-msu