By Tom Baumann
Part 1: Global Agriculture Conference
What do you do if someone invites you to a conference in Australia and they promise to foot the bill? Yes, that is easy, clear your schedule and go. I was joined by Zach Fleming from the University of the Fraser Valley and Timothy Kendrick from BW Global Structures.
So, off we went on a direct flight from Vancouver to Sidney and arrived in Brisbane the very next morning—17 hours ahead of Vancouver—where the Agricultural Bioscience International Conference (ABIC) 2015 was held. My first impression of Australia was that the economy class seats were actually comfortable for someone 196 cm tall and . . . let’s just say . . . on the heavy side. Thank you, Qantas!
The topic of the conference was mostly to do with hydroponics; however, as we eventually discovered, many other modern techniques were discussed as well. And to our big surprise, the presentations were not just concerned with greenhouse production, but also included field-grown food under protective structures.
Our presentation was on the first day, and we spoke about modern covering materials for greenhouses—something that we had tried out at the University of the Fraser Valley before. The talk was very well-received and many questions were asked about insulation factors, light diffusion/haze factor and longevity of the materials. As there was a large contingent from Wageningen Research University in Holland present, the discussion on the merits of glass vs. plastics continued on and off for two days.
At this time, there is very little comparative research available, especially when it comes to multi-layer materials. However, what seems very clear is that the conference participants were keenly interested in trying the materials themselves and there is now a trial going on in Cairns, Australia. The major factors discussed about greenhouse covering were:
- Light transmission (which, at this time, is highest with glass and lower with plastics).
- Light diffusion: i.e. the light is shed into the greenhouse from all directions, allowing light deeper into the plant canopy which reduces “top-loading” and possible burning of the plant tops. Plastic materials have up to 90%+ light diffusion and glass is at 70%. Some universities are conducting trials where special foils are adhered to the glass to increase light diffusion.
- Cost: plastics are higher in cost compared to regular glass and lower than tempered glass, especially for roofs.
- Insulation factors: double layer plastic has the advantage over glass as there is insulating airspace between the layers and none in glass.
- Replacement: plastics need to be replaced after 15 years or so, depending on materials, and glass can last 50 years.
- Weight: plastics are much lighter than glass, so the structure would not have to support as much weight.
- Air tightness: glass requires gaps and there is actual air exchange between panes, plastic can cover the area tightly, thus allowing for better humidity and heat control.
- Plant reaction: in our own trials at UFV, we found less stretching of the plants (cucumbers, tomatoes and peppers) which led to more nodes and more reproduction per stem segment. Stems were more sturdy and leaves did not yellow or brown and stayed productive for the life of the plant—likely because the light penetrated to the bottom of the plant, rather than focussing on the tops of the plant only.
Our colleagues agreed with us that production can be improved by as much as 30% with light diffusion; however, why and how is not yet completely clear. But we do know that for every 1% loss of light we lose 1% of yield, so it matters most what light the plants can capture on their leaves.
With a completely tight greenhouse, we can potentially recapture all water (except that being sold with the vegetable fruit) making this a hit in countries dealing with water shortages. This means all water losses from evaporation and transpiration may be captured and re-irrigated to the plants. Imagine that in a desert climate—or in BC this past summer when we were at Stage 3 water restrictions.
The air tightness also allows for CO2 control at its finest. The CO2 drawn from the boiler stack and injected into the greenhouse actually makes for increased production, taking CO2 out of the atmosphere and back into plant matter.
With double layer insulation and proper attachment to the greenhouse super structure, it is possible to break all outside contact to the cold of winter or the heat of summer and save lots of energy for the operation.
In the end, after these discussions with colleagues, we find that there is much we do not know and we look forward to working with the Dutch colleagues. Many other subjects were discussed, including:
- How to grow food indoors.
- Greenhouse vs. no greenhouse.
- How to grow hydroponically vs. aeroponically.
- What happens if we add one more component to this and grow fish or crustaceans in the greenhouse in combination with vegetable crops?
The delegation from BC had the ears of the conference attendees during a discussion on what kind of light might work best for greenhouse production and mainly focussed on LED lights. As one speaker was not quite certain on the usefulness of UV light in the greenhouse crops, one of us added that in BC the cannabis growers are quite well aware that a bit of UV light on the plants at certain times increases the harvest of the legal, medicinal crop. We had more attention at that moment than during the rest of the week!
Speaker after speaker shared their expertise and trials and pointed out the benefits and pitfalls of the sometimes very novel growing techniques they were advocating. We met many an entrepreneur at the conference interested in food production in crowded places like Hong Kong, Singapore and the like.
The one aspect that I considered while listening to the presentations was that it will take a lot of money to have fresh food grown locally for everyone. Right after I thought this, we heard from several speakers that food prices were already astronomically high in some places and shipping fresh food was extremely expensive; so, local production does make sense.
As always at these conferences, some of the proposed ways to grow food were out of this world; however, it stimulated discussion and when narrowed down to pure economics, some were dismissed and other ideas embraced by the audience.
A trade show ran concurrently with the conference and a global offering of companies was present. I don’t know how many people we talked with, but this is where modern agriculture was happening! New fertilizers, novel growing techniques, companies from Holland, China, Germany, Australia and elsewhere in the world were present. A great addition to the conference!
Part 2: Field Trip Anyone?
As part of the conference, we had signed up for a field tour to various protected growing enterprises. Finally, for the first time, we saw daylight and landscapes, streets lined with eucalyptus trees, signs warning of koala crossings and kangaroos in the distance. Buses left the conference venue at 7 am (typical for an agriculture conference).
Passing through endless fields of sugar cane and the occasional grazing operation, we made our way south to an herb growing place. In an otherwise dry landscape it was a pleasant surprise to end up at a place that smells like pizza and spicy food! They grew herbs of all kinds in sand with irrigation and a recapturing system, on table tops under a Venlo-style glass greenhouse cover, and harvested them sequentially year round. The temptation to start grazing and asking for bread with that was huge, but we all behaved, more or less. Mostly because we were promised “tea” at the conclusion of the visit there. Not only was the growing system something to behold, but the greenhouse also had its own automatic roof cleaner—as the area is one big dust bowl. They also had solar energy collectors on the roof of their offices and sorting rooms, and save themselves lots of cash that way. So all in all, this place literally left a pleasant taste in my mouth!
Our second stop an hour later was for lunch at a tomato greenhouse with double layer polyethylene covering and hanging troughs where the tomatoes grew. It was quite the treat to see some of their modern growing techniques, although I was unimpressed with tour participants walking between rows and touching plants and fruit. Food safety is so important these days and participants should know better. However, this being an international conference, there were folks from countries that do not have the stringent rules that Canada has when it comes to food safety. This too was clear from discussions on the busses.
The beauty of this place was that they also have a destination farm on the premises with lunch facilities, gift shops, grocery shopping and the likes. Customers do not get a tour through the greenhouse unless a tour guide is present. The food was superb and the place predominantly hires those with various levels of disabilities who proudly served us. What a great combination of farm, employment opportunity and destination farm experience.
Lastly we stopped at a place that grows vegetables out of doors with not much more than a shelter from polyethylene above. What an incredible place this was, close to the ocean, windswept with acres upon acres of food hydroponically grown on tables in a most interesting fashion. Not modern looking, but simple and efficient, and yet the technologically was quite advanced.
A long bus ride back to the conference centre with much discussion between the global ridership showed just how exciting the tour had been. Growing the future of food globally, water recapturing, soft pest and disease control, great food safety and growers that are proud of what they are doing and proud to show it off to an international audience. We are invited back for 2017 and we will make every effort to return for another a great conference and tour! Thank you to the many friends and connections we made in Australia!
[infobox title=’Tom Baumann’]Tom Baumann has spent most of his agriculture career as a horticulturist specializing in berries. His company, Expert Agriculture Team Ltd., provides may services to others including advice, trouble shooting and aids in claim situations. Tom also teaches full-time at UFV Chilliwack as an Associate Professor in the Agriculture Department.[/infobox]