Seasonal High Tunnel Systems for Crop Production (798) Update on interim standard 1
VT is Participating One of 38 states involved with 3 year pilot 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 2
Brandon Smith 3 Brandon Smith
Purpose Extend the crop growing season Improve plant quality Improve soil quality Improve water quality from reduced nutrient and pesticide transport Produce more food locally (energy savings) Know your Farmer, Know your Food 4
Condition Where Practice Applies Existing cultivated cropland where extension of season 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 5
Condition Where Practice Applies This practice does not include greenhouses or low tunnel systems that may cover single crops rows. Brandon Smith 6
Criteria The seasonal tunnel structure must be planned, designed, and constructed in accordance with manufacturer s recommendation Producers will build themselves Tunnel shall be constructed of metal, wood, or durable plastic and be at least 6 ft in height 7
Installation Will be installed according to manufacturers instructions Example of what a grower can expect to receive growinggroceries.com 8
Elements of a High Tunnel Shape Ground Posts and Bows Purlins and Truss Supports Sidewalls and Endwalls Ventilation and Access Covering (Polyethylene Plastic) 9
Shape Qounset (Round Hoop) or Gothic (Peak) Typically 14 to 34 ft wide, 28 to 150 ft long Gothic styles deal with snow load better Requires additional bracing 12-16 ft at peak Farmtek.com 10 Brandon Smith
Snow Damage hightunnels.org John McLean,UNH Snow shall be removed from the around the tunnel structure as part of an operation and maintenance plan 11
Criteria In climate conditions where snow loads may damage the structure, the tunnel cover shall be removed at the end of the growing season Counter intuitive tunnels are used for season extension (winter broccoli, spinach) No damage with gothic style, no plastic removal NH will provide FA for gothic style only 12
Ground Posts Galvanized steel pipe Sunk ~3 ft. deep with ~ 1 ft. above ground Caution with cement: change tax classification from temporary to permanent No cement with NRCS FA cook.rutgers.edu 13 cook.rutgers.edu
Bows or Rafters Galvanized steel Inserted and attached to ground posts Forms ribs or shell Spaced 4-6 ft apart cook.rutgers.edu For more construction photos see: http://www.cook.rutgers.edu/~horteng/hightunnel1.htm Construction photos in this presentation used with permission from Wesley Kline 14 cook.rutgers.edu
Criteria VT NRCS will not provide FA for a high tunnel with bows or ground posts made of wood, plastic (PVC), or aluminum FA is not available for producers who want to bend their own galvanized steel pipe 15
Purlins and Truss Supports/Braces Purlins stabilize structure lengthwise At least 3 including ridge Trusses/Braces stabilize structure crosswise At least every other bow purlin Truss support and brace Brandon Smith 16
Sidewalls Generally 4-6 ft high Manual roll-up curtains (gearbox) Baseboards at bottom of structure Hip boards/ribbon boards at curtain top Materials vary 17 Brandon Smith
Endwalls Manually operated louvered vents are acceptable For additional ventilation and access (vents & doors) Wood or steel Covered with 6 mil polyethylene or polycarbonate hort.cornell.edu Plywood or ripstop organics.tennessee.edu translucent fabric? 18
Plastic 6 mil, 4 year UV stabilized polyethylene Generally attached with polylock or wiggle wire or U-channel spring pucketgreenhouses.com 19 pucketgreenhouses.com
Criteria As a mimimum, a 6-mil greenhousegrade, UV resistant polyethylene cover will be used Standard from most manufactures 20
Payment Rate Maximum of 2,178 square feet for a farming operation For a gothic style high tunnel with roll up sides and endwalls Historically Underserved (new and beginning farmer, limited resource farmer, etc.) will get $3.40 per square foot, all others will get $2.90 per square foot up to the 2,178 square foot limit. 21
Payment Rate (Cont.) Payment rate cap Tunnel can be larger Can have multiple tunnels Can already have a tunnel 22
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 23
Criteria Runoff shall be directed away from tunnel to avoid ponding Surface or underground outlets Protected ground surface Collected for irrigation If runoff empties onto ground surface, a detention basin, storage reservoir, or stable outlet shall be provided 24
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 (pollinators?) 25
Considerations Plan appropriate measures to address: Crop rotation Irrigation water management Nutrient management Pest management Runoff from structure Pollination and beneficial insect habitat See EQIP and AMA practice list for associated practices 26
High Tunnel Sources It s a greenhouse-type frame Cold Frame plus accessories Rimol Greenhouses, Hooksett Noreaster Ledgewood Farm, Moultonboro Griffin Greenhouse, Farmtek, Atlas Sources at hightunnels.org 27