Meetings in the Netherlands

Following Fruit Logistica in Berlin, the group of 6 representing greenhouse growers from both TomatoesNZ and Vegetables NZ and myself, travelled to the Netherlands to meet a wide range of suppliers. We went to see leading research, new innovations and heard about what is next for the GH industry. Front of mind for us was the crossroads that the NZ GH industry is currently facing, with many of our greenhouses near or even beyond the usual lifespan of this infrastructure. This trip was in part to better see and understand what the latest options are for greenhouse tech, and also to understand how Dutch growers are managing their energy inputs.

Greenhouse tech

Hygiene is considered at the planning stage of new GHs rather than as an ‘add on’. That includes an area for staff to change into uniforms, the installation of washing stations that can’t be bypassed and different employee zones to avoid the staff from different compartments mixing. If trucks need to come onsite, this is also considered so that a one way system can be implemented. All of this is to ensure that hygiene is top priority for keeping all diseases out of the GH.

Screens

Are standard with new GHs, at least one but usually 2 or even 3. The GHs that we saw had LED lighting (we didn’t see the sun when we were there, so understandable!) so 1 screen would be for black out as per legislation. 1 or 2 screens are for saving energy, and some greenhouses have a pest protection screen. An alternative to this were netted vents, which also seemed to be common. Although the humidity in the Netherlands isn’t as bad as it is in parts of NZ, so this would be something to consider with both screens and netted vents. It’s worth asking screen suppliers if they have screens which absorb moisture and what effect if any this has on the lifespan of the screen. A number of growers in NZ have had screens retro fitted, so it is also worth having conversations with your networks for advice. One thing to note is that every screen has NEN ratings which are independently determined so allows comparisons; look at the diffuse stat how the light entering your GH will be impacted.

Screens are standard with new GHs, at least one but usually 2 or even 3. The GHs that we saw had LED lighting (we didn’t see the sun when we were there so understandable!) so 1 screen would be for black out as per legislation. 1 or 2 screens are for saving energy and some greenhouses have a pest protection screen. An alternative to this were netted vents which also seemed to be common. Although the humidity in the Netherlands isn’t as bad as it is in parts of NZ, so this would be something to consider with both screens and netted vents. It’s worth asking screen suppliers if they have screens which absorb moisture and what effect if any this has on the lifespan of the screen. A number of growers in NZ have had screens retro fitted so it is also worth having conversations with your networks for advice. One thing to note is that every screen has NEN ratings which are independently determined so allows comparisons; look at the diffuse stat how the light entering your GH will be impacted.

Energy sources can have an influence on location. We saw GHs that were located near data centres; the GH operation provided the data centres access to water for cooling purposes and the resulting warmer water could then be piped through the GH for heating. Geothermal bores have become commonplace in the Netherlands (NL) as another source of heat. In NZ we have low temperature geothermal relatively close to the surface  but in the NL they drill down for several kilometres. The Dutch government however has an insurance scheme running that pays out for any drilling that is undertaken that doesn’t find a geothermal source. Buffer tanks are needed with geothermal heating as unlike gas or recycled oil, the tap can’t be turned off once accessed.  For smaller growers situated near each other, heating and CO2 supply and storage were sometimes shared meaning the costs of these were also shared. We visited a site that was capturing CO2 from flue gas and storing it in huge balloons https://www.greengasliquids.com/galloxol/

We also visited Botany, a trial site aiming to reduce the energy input in a tomato and cucumber GH by 40% for lighting (changed from HPS to LED) and heating. For the heating, they achieved this reduction purely by drying out the GH air. Research has shown that 60% of heating can go simply on getting rid of moisture, leaving just 40% of energy input into raising the temperature. An air exchanger is used to suck out the GH air, dry it, heat it and then blowing it back in. When we visited it was a chilly 2 degrees outside with a light frost, in the GH the pipes were cold but the air was dry and warm. It’s worth checking for updates on this project here:  https://www.grodan.com/global/knowledge/collaborations-and-trials/Low-energy-tomato-growing/

Finally, in terms of robotics the most promising machine we saw was the MetoMotion picking machine supplied by Ridder https://grow.ridder.com/ This is different to other harvesters as the aim was never for it to pick 100% of the crop. The thinking is that this would never result in an affordable product that would get to production. Instead having a machine that can pick 80% of available truss tomatoes with 5 machines covering 5 hectares, supervised by one human, working 2 x 8 hour shifts is more realistic. If all the costs involved with labour (HR, sick days, holidays, managers etc) are considered, there will still be a saving in labour costs, even with humans going in to finish the 20% of picking at the end of the week. This is another one to watch