tips for tunnels of all types - uvm.edu

Tips for Tunnels of all Types

Vern Grubinger

December 10, 2014

plastic mulch row covers

low tunnels caterpillars field tunnels

hoophouses high tunnels greenhouses

Seasonal

structures

• low tunnels

• caterpillars

• field tunnels

(Haygrove)

Year-round

structures

• hoophouses

• high tunnels

• greenhouses

low tunnels ~$0.50/sq. ft.

Johnny’s

Seeds

“quickhoop”

Bender

½‘’ conduit

+ Agribon

overwintering kale, mustard, onions, spinach etc.

planting date has an effect on yield

Ruth Hazzard, Univ. of Mass. and Becky Sideman, Univ. of NH

varieties differ, too (overwintered onions)

caterpillar tunnels ~ $1/sq. ft.

Windflower Farm in upstate New York

Oriented so ends face the prevailing wind.

plastic must be removed before winter

Windflower Farm crops and structures

Crop Low Tunnel Caterpillar Hi Tunnel

Tomato XX (trellis) XXX

Pepper X XX

Eggplant X XX

Cucumber XX XX (trellis) XXX

Melon XX XX (trellis)

Squash XX XX

Spring Greens XX XX

Fall Greens XX XX

Winter Greens XX

Spring Onions XX XX

field tunnels aka Haygroves ~$1/ sq. ft.

single or multi-bay >1 acre

wind is a concern with

any 3-season structure

keeping the rain off…

season extension…

manual ventilation required

hoop house ~ $1.50/sq. ft.

low height, quonset shape, no sidewall vents

declining popularity:

high humidity

poor ventilation

low head room

high tunnels ~$2/sq. ft.

gothic, roll-up sides, plastic, drip

Ledgewood Farm frame with gothic peak, high sides

supplemental air, ground heat?

FarmTek quonset high tunnel

home made wood frame – Pete’s Greens

plastic greenhouse ~$10/sq. ft.

tunnel vs. GH

electricity

heat

foundation?

size?

high side and ridge vents (poly-vent tubes)

HAF, bottom and air heat, zoned drip

tomatoes in Poly-Tek greenhouse

‘winter’ greens in Harnois greenhouse

tight, low surface:volume, high sides and peak

Rimol greenhouse

wide span, endwall peak vents, tractor access

Rimol automated roll up sides

glass greenhouse ~$25+ / sq. ft.

Longwind Farm, organic GH tomatoes

heat pipes/cart rails, environmental controls

Full Bloom Farm, organic basil

rolling benches, potfillers, lighting

design for your crops, markets, budget

long season ‘tropical’ crop

‘season extension’ of perennials

unheated spring-planted crops

unheated ‘winter’ crops

transplants on heated slab

Key Considerations

• Site

• Structure

• Environmental Controls

• Soil / Crop Nutrition / Water

• Pests

• Labor / Management

• Costs and Returns

got drainage, compaction?

perimeter drainage

space for snow, mowing, access, expansion?

worst case snow, ice, and/or wind?

soil fertility and crop nutrition

‘super-charged’ soils

saturated media test vs. field soil test:

soluble vs. reserve nutrients

0

200

400

600

800

1000

1200

1400

1600

1800

2000

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73

K in greenhouse ‘soil’ 75 samples 2008-09

sanitation is a key to pest management

No weeds inside houses

Well, almost

no weeds...

mow around houses

hoses off the ground

monitoring is another key to pest management

heat rises

fans pull air with the least resistance

furnaces fail,

fuel runs out!

heat-activated vent,

temperature alarm

tunnel edges take time to weed

why waste fuel?

small cracks matter

energy conservation

perimeter insulation

bench heat, insulated knee walls

use step controllers or accurate thermostats

renewable fuels like shell corn, wood pellets

solar hot water + biomass heat

if you’re a logger in the winter…

balance cost, Btus, materials handling, reliability

www.uvm.edu/vtvegandberry