seasonal high tunnel systems for crops update on interim standard 798 technical and program guidance...

Seasonal High Tunnel Systems for Crops

Update on interim standard 798

Technical and Program guidance

National bulletin: 190-10-10 National Bulletin: 190-10-12

NRCS IdahoOctober, 2010

Seasonal High Tunnel - Definition:

A seasonal polyethylene covered structure with no electrical, heating, and/or mechanical ventilation systems that is used to cover crops and extend the season in an environmentally friendly manner

• Practice lifespan: 4 years

•Currently (2011) only available under the Organic EQIP payment schedule.

- Improve plant quality

- Improve soil quality

- Improve water quality from reduced nutrient and pesticide transport

- Improve air quality through reduced transportation input

- Reduced energy use through local consumption

Purposes

• Cropland where the growing season extension is needed due to climate

• Crops grown in natural soil profile–Specialty crops like vegetables and small fruits

• Raised beds allowed, but not crops on benches or in pots

Condition Where Practice Applies

• Tunnel shall be constructed of metal, wood, or durable plastic and be at least 6 ft in height

Criteria• The seasonal tunnel structure must be planned, designed, and constructed in accordance with manufacturer’s recommendation

• Shape• Ground Posts and Bows• Purlins and Truss Supports• Sidewalls and Endwalls• Ventilation and Access • Covering (Polyethylene Plastic)

Elements of a High Tunnel

• “In climate conditions where snow loads may damage the structure, the tunnel cover shall be removed at the end of the growing season”

• As a minimum, a 6-mil greenhouse-grade, UV resistant polyethylene cover will be used•Standard from most manufactures

Criteria

• Maximum 2,178 square feet for a farming operation• Idaho NRCS has two payment rates:

1. Up to 1,000 square feet2. More than 1,000 square feet

Payment rate cap– Tunnel can be larger, but only pay up to 2,178 sq ft– Can have multiple tunnels– Can already have a tunnel

Payment Rate

Installation Considerations

Orientation

• NS for main season, EW for off season, maximize airflow crosswise• Distance from structures/shade

–2x height of nearest structure• Quality soil• Access to water for irrigation• Drainage

• Runoff shall be directed away from tunnel to avoid ponding

– Surface or underground outlets– Protected ground surface– Critical area planting

− Grassed waterways• If runoff empties onto ground surface, a detention basin, storage reservoir, or stable outlet shall be provided

Criteria

• Surface or ground outlets such as rock pads, rock filled trenches with subsurface drains, concrete and other erosion-resistant pads, or preformed channels may be used

• Seeding and vegetation shall be established on all disturbed earth surfaces

Criteria

• Plan appropriate measures to address:– Conservation crop rotation– Irrigation water management– Nutrient management– Pest management– Runoff from the structure

• Rotate location of the tunnel to reduce disease build up.

Considerations

For general information and suppliers of high tunnel systems see web sites:

hightunnels.org

University of Idaho http://www.extension.uidaho.edu/homegard.asp Utah State University https://extension.usu.edu/yardandgarden/htm/vegetables-fruits-herbs

High Tunnel Sources