Supplemental Heat for Winter Greens Production: What's the Cost?
Ethan Grundberg, Vegetable Specialist
Eastern New York Commercial Horticulture
Winter greens in high tunnels at then Poughkeepsie Farm ProjectThere seems to be little agreement among winter greens growers regarding the true costs and potential value of using supplemental heat all winter. With support from the Northeast Sustainable Agriculture Research and Education program (NE SARE) and the generous cooperation of the Poughkeepsie Farm Project (PFP), we tried to start gathering some data to add to the high tunnel heating debate. We tracked yield, soil nitrate availability, total nitrogen uptake, propane use, and soil temperature all winter in the two identical side-by-side 42'x196' double layer inflated poly Harnois high tunnels with one tunnel set to 33 degrees ambient air temperature and the other set to 40.
The data from the trial is still being analyzed, but here are a few key results that have emerged:
- Maintaining adequate soil moisture and, ideally, living roots in the high tunnel before planting is necessary to preserve the soil microbial community that makes nitrogen available for plant uptake.
- Soil nitrate levels were not significantly or consistently different between the two temperatures; however, total nitrogen uptake in the warmer tunnel was higher for curly kale, spinach, and especially for Salanova lettuce.
- The warmer tunnel yielded three harvests in the same time that the cooler tunnel yielded only two.
- It took 979 gallons of propane to heat the tunnel to 33 degrees from November through March. It took 2.1 times as much propane to add the extra 7 degrees to reach 40 over the same period.
- Fertilizing to 70 pounds/acre of nitrogen in September provided sufficient nitrogen to kale, spinach, and Salanova until mid-February.
- Targeted early spring fertigations with soluble Chilean nitrate carried those crops to maturity in early April
A big thanks to the great crew at PFP for all of the help tracking yield! Going forward, a group of vegetable specialists with Cornell Cooperative Extension hopes to continue to investigate fertility management in winter high tunnels generally and specifically the interplay between supplemental heating and nitrogen. If you are interested in collaborating, please reach out to Ethan at eg572@cornell.edu.
This article is from the April 26, 2018 edition of ENYCHP Vegetable News. To read the full newsletter, CLICK HERE.
Apples
Apricots
Asparagus
Beets
Blueberries
Broccoli
Brussels Sprouts
Cabbage
Carrots
Cauliflower
Cherries
Cucumbers
Dry Beans
Eggplant
Ethnic Vegetables
Garlic
Grapes
Horseradish
Kohlrabi
Leeks
Lettuce / Leafy Greens
Melons
Nectarines
Onions
Parsnips
Peaches
Pears
Peas
Peppers
Plums
Potatoes
Pumpkins / Gourds
Radishes
Raspberries / Blackberries
Rhubarb
Rutabaga
Snap Beans
Squash - Summer
Squash- Winter
Strawberries
Sweet Corn
Sweet Potatoes
Tomatoes
Turnips
Upcoming Events
ENY Orchard Soil Health and Beneficial Fungi Meeting
August 15, 2024 : ENY Orchard Soil Health and Beneficial Fungi Meeting
Peru, NY
Join the members of CCE ENYCHP and the Cornell Soil Health Program for a field meeting on the basics of soil health, the potential benefits of mycorrhizal fungi, and an update on the current project status of our SARE grant on orchard mycorrhizal products.
This meeting is intended for farmworkers, young and beginning orchardists, and experienced orchard managers wanting to learn about the basics of soil health and mycorrhizal fungi within the orchard.
North Point Community Farm Twilight Meeting
August 19, 2024 : North Point Community Farm Twilight Meeting
Plattsburgh, NY
North Point Community Farm Twilight Meeting
Monday, August 19th 4-7 pm (rain or shine)
2172 Military Turnpike, Plattsburgh, NY 12901
$10 per farm
Join us for a tour of North Point Community Farm, a diversified vegetable, berry, and flower operation in the North Country. Farmers Marisa and Mike will give us an overview of their decision-making as they expand their business, increasing their high tunnel production, investing in new tillage equipment, and transforming an old dairy barn into an efficient wash-pack shed with food safety in mind. We'll end the evening with local food refreshments and an opportunity to network with growers from NY and VT.
DEC credits: 1.5 credits in categories 1A, 10, 23
Late Summer Orchard Meeting
August 21, 2024
Fonda, NY
Join us for our last get together of the summer before we're in the thick of harvest. At this meeting, we will tour Sand Flats Orchard with manager Mitch Hoffman, and we will then discuss late season pest management tasks with our experts from the HVRL and Cornell AgriTech.
DEC Credits: 1.5 credits in categories 1A, 10, and 22.