Improve Your Bottom Line with Sustainable Practices

These tips can help you improve the long-term profitability of your greenhouse operation.

By adding advanced hydrogels like STOCKOSORB® into the media mix, growers can reduce the amount of water used and improve quality control through to retail. Image:

Sustainability has been a big buzzword for years. While many associate it with environmental consciousness, it actually goes much deeper than that. To be sustainable is to invest in the long-term viability and profitability of your greenhouse operation.

But that doesn’t mean growers have to spend huge amounts of money to become more sustainable. Even the smallest efforts, such as taking a closer look at irrigation efficiency or tweaking nutrition programs, can make a big difference in the long run.

Nutrient Management

Fertilizer is expensive, so it makes good business sense to use just the right amount. Here are a few tips to follow from the UMass Extension Greenhouse Best Management Practices Manual, compiled by Tina Smith and Paul Lopes:

  • Check fertilizer injectors before each crop cycle to make sure they’re working correctly. The UMass manual recommends using a conductivity meter to test the electrical conductivity (EC) of the fertilizer and comparing those results to a fertilizer manufacturer’s EC chart.
  • Plan fertilizer application based on plant growth. Fertilizer application should be matched with plant nutrient needs as the plant gets bigger. Plant growth rate and environmental conditions should always be considered as part of your nutrient management program.
  • Choose the right product for the crop being grown. Not all controlled release fertilizers are created equal. Be sure to choose the right product for the crop being grown, and follow rate instructions to ensure you’re applying the right amount.
  • Limit fertilizer loss. To increase fertilizer efficiency, subirrigation is your best bet. In a subirrigation system, all the liquid is contained in the supply tank, which helps eliminate runoff and waste and allows for a 25% to 50% reduction in fertilizer use, compared to an overhead watering system.

Pest and Disease Management

  • Inspect plants before they’re put into production. Check for signs of diseases or pests such as mites. Infested plants should be quarantined and treated with a pest control product before being introduced into regular production areas to reduce the spread of pests and diseases.
  • Scout for pests often. UMass recommends checking propagation areas every three to four days.
  • Wash your hands. If you handle infected plants, be sure to wash your hands thoroughly or wear disposable gloves to avoid spreading pests or diseases to healthy plants.
  • Keep good records. At the end of the season, review your scouting records to determine which pests were most problematic. This can help you create a plan of attack the following year to stay ahead of damaging pests and diseases.

Energy Management

There are some very simple, low-cost things growers can do to improve energy efficiency in the greenhouse. Here are a few UMass recommends:

  • Prevent or reduce air leaks. Simply closing doors behind you in the greenhouse can save tremendously on heating costs. Also consider weather-stripping doors, vents and fan openings to reduce air leaks.
  • Keep glass and plastic maintained. Repair any broken glass in the greenhouse, and make sure there are no holes in plastic coverings.
  • Add plastic to older greenhouses. According to UMass, adding a layer or two of plastic over glass houses can reduce air infiltration and heat loss by 50%.
  • Add insulation. Insulating the foundation with polyurethane or polystyrene board to 18 inches below ground can increase soil temperature near sidewalls by 10°F during cold months. Insulating sidewalls can save a significant amount of money, too. According to UMass, 2 inches of foam insulation applied to a 3-foot-high sidewall in a 28-foot by 100-foot greenhouse can save as much as 400 gallons of fuel in a year.

Water Management

Wise water management not only saves water, it can reduce labor costs, as well. The UMass Extension Greenhouse Best Management Practices Manual offers some recommendations:

  • Consider crops grown, weather conditions, time of year, and the environmental control system to determine the amount of water needed. Be sure to design your irrigation system to function well during peak use. It’s recommended to have 0.3 to 0.4 gallons of water per square foot of growing area per day to accommodate for the peak use rate on the hottest day.
  • Reduce radiation levels. To decrease the amount of water needed, consider using shading to reduce radiation levels. Shade can reduce the rate of evapotranspiration, meaning plants need less water.
  • The type of irrigation system you use can play a big role in how much water you use. With an overhead sprinkler system, only 20% of the water applied may actually reach the soil in plants that have large foliar canopies. Drip systems, on the other hand, allow all the water to reach the soil, and sub-irrigation or flood floor systems allow you to recycle excess water. An investment in an efficient irrigation system will result in significant cost savings in the long run.
  • Pay attention to leaching. It’s generally recommended that growers let 10% of applied water leach out to remove excess salts and fertilizers. However, much more than this is often leached, which increases water use dramatically. Keep in mind that water needs will vary based on the type of growing media used, too. Adding hydrogels to the media mix can also reduce the frequency of irrigation, which in turn reduces the leaching of valuable nutrients.

Boost Sustainability with Hydrogels

In addition to the above recommendations, growers might also want to consider using water-absorbing hydrogel such as Evonik Industries’ STOCKOSORB® in the growing media. In the soil, hydrogels absorb water and nutrients, which are then slowly released to plants on demand, when they need it. Growers have reported that by using STOCKOSORB®, they are able to improve quality control all the way through retail and reduce plant losses, while they also used less water and irrigation labor.

This is just a small list of things you can do to create a more sustainable growing operation. Implementing even a few of these suggestions could help you reduce costs and improve overall profitability while helping the environment, too.

Make your water go farther while improving the health of your plants. To find out more about how STOCKOSORB® advanced hydrogel technology can help your growing operation, contact Lynn Royal at 336-335-3781, email [email protected].

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