Sliding high tunnels extend the growing season, speed crop growth, reduce plant stress, and promote soil health using passive solar heating and passive ventilation.

Sliding High Tunnels

What is a high tunnel?

High tunnel components

  1. Steel hoops covered by greenhouse plastic
  2. Roll-up sides to facilitate passive ventilation
  3. Spans several growing beds to allow soil-based production and farm worker movement

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Cool season greens in high tunnel

High tunnel benefits

  • Extends the growing season to increase income potential
  • Reduces crop stress and disease pressure by protecting crops from wind and rain
  • Increases heat accumulation to speed crop development and increase diversity of cropping options
  • Extends period when fresh, locally-grown produce is available

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Cucumbers in high tunnel

Why moveable?

  • Allows for optimal utilization of high tunnel structure
  • Exposes soil to natural processes -- such as rainfall, frost, and direct sunlight -- that help maintain soil health by leaching salts and killing soil-borne disease
  • Allows rotation of crops that benefit from season extension with crops that do not

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Bed outside high tunnel

Why solar panels?

  • Powers electric motors that raise and lower roll-up sides and open and close vents for passive ventilation;
  • Powers a greenhouse computer that manages ventilation in response to interior temperature
  • Charges a battery to allow these processes to continue when the sun isn't shining

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High tunnel in winter

Crop rotation

  • Nine year crop rotation through nine plots
  • Warm season and cool season crops alternate
  • Each tunnel is moved in spring and fall, so it is anchored in three different positions over the course of a year:
    1. Winter/spring position (cool season crops, carried over from previous fall)
    2. Summer position (warm season crops)
    3. Fall/winter position (cool season crops, carried into following year)

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High tunnel positions

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High tunnel crop rotation circle

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high tunnel rotation table

High tunnel rotation table. Bold face indicates high tunnel position.