New England Vegetable & Fruit Conference 2017

In addition to attending the Great Lakes Expo, UVM Ag Engineering attended the New England Vegetable & Fruit Conference in Manchester, NH. This conference is very well suited for the small-scale and highly diversified farmers that populate the North East.

This conference is filled with a variety of vendors at the trade show, presentations covering specific details of individual crops and varieties, and even talks on designing your farm with an eye on food safety. Another interesting activity that went on was the farmer to farmer sessions that are not presentations but a lead conversation to discuss what works and what doesn’t on your farm. A lot of tips, tricks, and common complaints are all brought up and shared during this literally circled up conversation.

If you’ve never been here are a few photos from the event, which was very snowy in mid-December.

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Here is a short highlight video from the conference!

 

The presentations that Chris gave at this conference can be seen below. This first one is all about designing your facilities with a food safety mindset. If you’ve never thought about your infrastructure Continue reading New England Vegetable & Fruit Conference 2017

The AZS Rinse Conveyor at Picadilly Farm


Picadilly Farm is owned and operated by Jenny and Bruce Wooster since 2006. Their farm is located in the South East Corner of New Hampshire in Winchester and has about 30 acres in production. They provide fresh produce to over 1,000 families through CSA shares spread across New Hampshire, Vermont, and Massachusetts.

Bruce reached out to share that he has an AZS Rinse conveyor and offered up his thoughts on the equipment as well.

Continue reading The AZS Rinse Conveyor at Picadilly Farm

DewRight Debut: From Product to Patent

This video is an episode from Across the Fence! It holds an interview with Judy Simpson as well as a description of the product.

The video below highlights the 9min segment specifically talking about the DewRight.

Read the write up from Vermont Business Magazine here.

Read the press release from UVM’s University Communications here.

Spring Cleaning – Farm Cooler Checklist

Whether your winter storage rooms are getting bare or you are making the transition from sweet corn to potatoes, what better time to give your cooler a once over than right now? Download the Farm Cooler Checklist to help guide your walk-through.

Highlights include:

  • Cleaning, sanitizing and inspection of surfaces
  • Checking the envelope
  • Inspecting refrigeration equipment inside and out
  • Checking over a CoolBotTM
  • Checking thermostats
  • Confirming drainage
  • Reviewing and possibly upgrading lighting
  • Considering energy efficiency upgrades

Improved Ventilation for High Tunnels

I have received many inquiries about how to improve ventilation of high tunnels from growers with tunnels that have only roll-up sides. The issues they are facing tend to be either high temp, high humidity or both, leading to plant stress or disease. These situations tend to be in less than ideal sites for ventilation and/or temperature control. For example, crowded lots with trees or other significant wind breaks close to the tunnel, high southern exposure (which can be good of course), and/or simply calm sites that provide little ventilation.

Keenan Meier Shutters with flanged seal highlighted.

Roll-up sides alone tend to work for tunnels on sites with generally good air flow. Diffusion between inside and outside does happen, of course, but is slow and unlikely to achieve good ventilation along the center of the tunnel, especially with dense vegetation later in plant maturity. But, I think of a tunnel in this instance a bit like a wood stove. Without a chimney-effect natural draft, you’re really only getting ventilation from the sides and only then if there is a decent breeze. Warmer air and, therefore, humidity will tend to collect in the canopy and peak.

Passive wax cylinder louver actuator. [Photo Credit: http://www.littlegreenhouse.com/accessory/vent2.shtml]
This probably is OK in many sites for most crops. But not always. In many cases gable vents will improve ventilation by acting as outlets for warm humid air in warmer seasons and by allowing for low volume ventilation in colder weather. I recommend a simple 24″x24″ gable vent (for a 30’x96′ tunnel) on each end wall, with a thermostatic wax cylinder actuator like the ones made by J. Orbesen Teknik APS available from LittleGreenhouse.com., FarmTek, and Agricultural Solutions among others  The actuators require no electricity, are relatively inexpensive and are passively controlled by the wax cylinder based on temperature.

At the very least, when building end-walls consider framing in a rough opening to accept a 24″x24″ in the end wall so that a future install is easier. If you want to skip the expense of a louvered, wax cylinder system, you can use a manually-controlled sheet of plywood to open and close the vent. If you go with a louvered vent, seek one that has a flanged seal it closes against. Keenan Meier, and Munters-Euroemme has such flanged, louvered dampers.

Munters Euroemme fan with flanged seal being pointed out.

These have zero daylight when closed which results in a solid seal. Most others on the market that I have seen have no such closure seal.

Fans

Fans in greenhouses and high tunnels generally perform two tasks: (1) circulation / mixing / stirring and (2) ventilation.

  1. Circulation / Mixing / Stirring – Sometimes referred to as horizontal air flow or “HAF” fans, these fans are generally hung from the inside horizontal structural tubing.  They only mix the air.  The benefit of this is consistent, well distributed growing conditions.  It also ensures that your control sensors are seeing the “average” conditions of the space. Remember that HAF fans work to mix the space (circulate the air) but don’t significantly improve ventilation. HAF combined with roll up sides can do the trick, but the site is the key. There needs to be a steady cross breeze for any significant air exchange to occur.
  2. Ventilation – Ventilation, or “exhaust” fans provide air exchange between the inside and outside. This is really important in controlling temperature (cooling) or humidity (drying).  The only way to remove heat or humidity from a standard high tunnel or greenhouse is by actively removing air from the space and bringing in outside air.  Ventilation (cooling) systems are covered very well by Bartok and Aldrich (p. 70).  Basic rules of thumb for ventilation are 8 CFM/ft2 (of growing space) for summer cooling and 2 CFM/ft2 for cooler months.

References:

Bartok, J., & Aldrich, R. (1994). Greenhouse Engineering, NRAES – 33. Natural Resource, Agriculture and Engineering Service (NRAES). Retrieved from http://host31.spidergraphics.com/nra/doc/Fair%20Use%20Web%20PDFs/NRAES-33_Web.pdf

Pumps and Pipes

A Taco 007
A Taco 007, shaken not stirred.

“Will the 007 be enough?”  is a common question in early spring as greenhouses around the region fire up and we do our best to keep seed trays and their cargo warm on the still-cool nights.  My mind instantly goes to “which movie?” And then I crash back to earth and realize this is a question about pumps and I am not Q. Continue reading Pumps and Pipes

Thermostats for Agriculture

I am often asked by growers and processors to recommend a thermostat for a greenhouse, cooler, or postharvest process use.  There are many to choose from and their specifications can be confusing. It is important to remember just what a thermostat does. It is essentially no different from the light switch on the wall with one very significant exception.  Instead of depending on a person to switch it from ON to OFF, we use a temperature measurement.  The accuracy of both the temperature setpoint (what you set) and the actual temperature (what the actual condition is) can be critical for production quality and energy efficiency. Continue reading Thermostats for Agriculture

Vermont Farmers Food Center Heats with Biomass

Rob Steingress (VFFC), Bill Kretzer (12 Gauge Electric) and Greg Cox (VFFC) perform final inspections before the initial firing of the boiler.
Rob Steingress (VFFC), Bill Kretzer (12 Gauge Electric) and Greg Cox (VFFC) perform final inspections before the initial firing of the boiler.

UVM Extension and others supported the recent installation of a 341,200 BTU/hr (output) multi-fuel biomass boiler at the Vermont Farmers Food Center (VFFC) in Rutland, VT.  The boiler heats the Farmer’s Hall building with the capability to use several alternative fuels to displace propane. The boiler was fueled primarily on wood pellets but was also able to feed and burn grass biomass pucks. This demonstration project carried a cost premium when compared to a typical propane heater installation.  That premium is paid back over time due to recurring fuel cost savings. A simple payback period of 2.2 to 8.0 years is feasible against a cost premium of $51,255 for the boiler depending on the fuel used and the amount of use. For more details about the project and the economic performance please see the report.

Continue reading Vermont Farmers Food Center Heats with Biomass

Grass and “Ag Biomass” Competitive with Wood Chips

Chris Davis (Meach Cove Trust) prepares the boiler and combustion testing equipment for a trial run of the new fuel.
Chris Davis (Meach Cove Trust) prepares the boiler and combustion testing equipment for a trial run of the new fuel.

Recent testing at the Meach Cove Trust has demonstrated strong economic and technical feasibility of grass-based biomass combustion fuels.  The use of solid, densified, cellulosic biomass fuels has been well demonstrated with wood pellets in residential and light commercial systems and wood chips in larger, often centralized systems.  The Grass Energy Partnership of the Vermont Bioenergy Initiative has been exploring an alternative form of fuel; grasses densified in a specially developed processor to take the form of 1.5”-2.0” round cylindrical pucks.  Grass fuels may be produced on otherwise marginal agricultural land, sometimes in perennial production and even in buffer strips offering environmental benefit.  Additionally, fuel can be made by densifying agricultural residue or biomass harvested from idle pasture or fields.  We have referred to this fuel as “Ag Biomass”. The testing summarized in this report has demonstrated the technical and economic feasibility of such fuels.

Continue reading Grass and “Ag Biomass” Competitive with Wood Chips