We doubled the time allotted to panel questions at our recent Organic & Biodynamic Winegrowing Conference, yet we still had some great questions left unanswered. OWNZ's coordinator Rebecca Reider followed up with five of our guest speakers to seek answers to the most popular questions remaining. We hope you enjoy these post event insights!
NB. Below is an abbreviated version. For the full article of our follow up questions, check out the latest edition of our magazine Organic Matters (due out mid August).
Q: Cover cropping seems paramount for soil microbiology and ecological diversity. What about low vigour vines in tougher soil and competition for moisture and nutrients?
Nigel answers: Cover cropping can take on many forms and should be tailored to soil type and what you are ideally trying to achieve. Each plant has a different rooting structure, from deep taproots that break up hard soil and bring calcium to the surface, to fine roots that build soil structure. It’s the combination of these which you need to play around with (or get advice on) to suit your site. A well planned cover crop will always give more back than it takes, whether it be nutrients or structure.
Q: Can you give further details on bronze beetle netting in the middle of the growing season?
A: We put the side nets on once we see the first few bugs flying around or before the first full moon near the end of October. They do not need to be clipped like you would do to exclude birds, just secure enough to stay in place. Attach the top to lifting wire on each side so top stays open, allowing any fast growing shoots to come out the top. Take them off once flights have finished and readjust your lifting wires to suit canopy growth and tidy up.
Q: How are your mealybug numbers at harvest? What do you believe is the biggest influence on this for you?
A: It’s very site-dependent, with the only hot spots within vineyards really showing up at harvest. The biggest influence on this is the carryover population from the previous year and the type of spring. Frosts and cool weather may slow down the breeding cycles early season, therefore potentially limiting numbers. It also depends on the amount of reproductive cycles there have been prior to harvest. There is a lot of great work being carried out on this, but there are also a lot of unanswered questions. Vaughn Bell and his team are doing a great job at trying to understand what influences numbers and what we can do about it.
Q: Has the mix of companies you sell to changed since you converted to organic, and what has been their response to the organic shift? Do the purchasers buy because you have organic grapes, and in turn make them into organic wine?
A: There has been a small change in the type of companies we sell to, but we have always had a good selection of large and small. With there being a lot more small producers on the scene, and many wanting organic grapes to give themselves the differentiation (or because it’s what they believe in), we have chosen to help these companies out. We see small high-quality producers as a benefit to the whole region and the New Zealand industry. However, many of the companies we sell to do not make organic wine; they blend our grapes with their own to make the final product, and they are buying the fruit for its quality, not its organic status. In the early days of our organic management, for some companies there was some nervousness that the product would be substandard; this fear has largely gone away. Because we are now known for producing organically, companies know what to expect.
Emiliana Organic Vineyards Q: Are you aiming to sequester more carbon in the soil (as a contribution to dealing with climate change), and do you see an opportunity to get recognition for that? Sebastián answers: Our goal is to increase organic matter in our soils. That will be achieved by increasing the amount of organic carbon in stable forms in our soils: compost, cover crops, prunings, reducing tillage and every form that we find that works to achieve that goal. This will contribute to the carbon farming of our soils (‘sequestering’ is a negative connotation that I don’t like to use). The recognition will be internal and will be communicated to our clients, but we will not put them in a carbon trading scheme. We would like to be carbon-neutral in our operations. There are some emissions that can be reduced, but not eliminated, so we could be able to compensate for them internally.
Q: How do you manage the timing of your biodynamic practices in the tight lunar windows over such a wide area? A: Very good question. The most fine-tuned biodynamic work is done for the top quality wines (3 out of 6 lines of wines), which are small productions. For larger volumes we try to do our best, but tasks such as pruning or harvesting is according to the availability of people, machinery and also the condition of the vines primarily.
Q: With drier warmer seasons in vineyards these days, any thoughts on clever use of irrigation/water use? Nick answers: I think mid-row sub-surface irrigation has a real place for helping to deal with these drier seasons. By putting water in the soil where it can be utilised efficiently and not growing a heap of weeds on the surface, hopefully less water is needed. Some real benefits to be gained from increasing soil organic matter, reducing cultivation, cover crops, crimping etc. – means more water can be stored for use later. Another key concept is the way irrigation is applied. Avoiding short cycles, try to do long soaks to drive roots down out of the topsoil where it dries out quicker. Monitoring is another key part to irrigation – I’ve found using plant-based cues to be more accurate; pressure bomb, infrared thermometers and visual inspections. Watching the tendrils can give a really good clue to water stress.
Q: What are your thoughts on trying to convert the unconverted and should we be even trying to start just with biological farming practice?
A: Yes I think biological farming is a great step for those ‘transitioning’; the unconverted need to take little steps to be clear in their mind that it works. Worst case I think is the grower goes cold turkey on ‘conventional’ inputs to become organic, and then fails because they don’t fully understand the concepts that biological/organic farming are based on. There are some amazing resources in the pastoral and cropping industries about biological or regenerative ag that could be applied in vineyards easily as the first steps towards removing those synthetic chemical inputs. I think the more conversations we can have between growers about biology in the soil, no matter how you describe the system you farm under, will have the greatest impact on the wider industry and converting the unconverted.
Q: Can you talk us through introducing dung beetles to our vineyard? How do you do it? Shaun answers: We have just developed a “winter beetle package”. This comprises an initial release of a colony of up to 400 Bubas bison. A second colony is recommended for release in year two to offset any potential for a two-year developmental phase underground rather than just one. This second colony, while highly recommended, isn’t mandatory.
Once ordered, the first colony will be posted via Priority Courier Post and the RD network for 2-3 day shipment once livestock are added to the vineyard. Handfuls of beetles will then be tipped onto fresh sheep manure. Bigger piles comprising logs and pellets is optimal. Beetles will then distribute during a 30 minute flight window just after dusk and just before dawn each day to find fresh manure each day, for as long as stock are in the vineyards. This species is active until stock and dung leave or the end of their active season in late October – whichever comes first. These adults die or hibernate underground. Meanwhile their scores of babies are developing in balls of sheep poo deep underground, and will emerge as new adults from April onwards the following season. How warm and dry the autumn is determines what percentage of developing young will emerge in year one or do so in year two, hence a two-year release package. We understand that mass emergence is triggered by a break in the season with cold temperatures and moisture. If the autumn is a dry warm one, then a higher proportion of the young stay put underground as a survival strategy that has been hard-wired into their genes for at least 50 million years.
Q: How much does it cost, and are all local councils involved in their provision to landowners?
$2,000-$3000+GST. In our winter beetle package, the first colony is valued at $2000. The second colony in year two will cost $1000 and is offered at half price as an incentive to order it as a $3000 package. Some councils so far are focused on dung beetles for commercial livestock farms and their use in reducing erosion and surface flow of contaminated water, and improving soil health and water quality. In 2018, Marlborough District Council engaged in a limited subsidy scheme for the first 10 farmers to embrace dung beetles in the district. To this point I am not sure the council is aware that dung beetles in a viticulture environment is now a reality. With some encouragement by viticulture organisations and lobbyists, then the council could respond with some form of subsidy scheme. MDC is a progressive council which we like to work with.
Q: Do you think dung beetles in vineyards with sheep in winter would help soil compaction from machinery?
A: Yes, dramatically so. This species nests in a range of 60-90cm beneath the soil surface. Their tunnels, bioturbation of subsoils, deposition of organic carbon and nutrients from sheep manure, and improvements to soil macropores, biota, root penetration and structure, has been shown to be significant.
Q: As an important indicator of soil health in Central Otago, how have you seen your soil organic matter change since the beginning of your organic and biodynamic journey?
Gareth answers: I haven’t been checking yearly, but from 15-18 years ago until last year we have found our organic matter levels have improved. They are so low in our soils to start with, so any improvement is dramatic.
Q: Can biodynamic preparations be made in a central location for multiple sites, or does each site have its own diversity?
A: If you are looking to be 110% correct, then each property should reflect each preparation. The manure from cows on one property may well be different from one 50 km away. The practicality of doing this while maintaining quality is not always good, though. So it could be better to centralise preparation-making with good inputs and people to make the very best. With large amounts of marc from each property, I would suggest at least making the compost separately, as this keeps the identity of each site correct.
Q: How important is it to follow the biodynamic calendar for various vineyard activities?
A: Follow the calendar with regards to making sure the preparations are applied correctly if possible. Look to make compost or turn compost on a descending moon phase. If you are working via the calendar and have just a small amount of a prep to finish, e.g. you’re putting preparation 500 over 32 hectares and it is changing to ascending moon, then just finish it. Better to have you and the team in the correct head space, than to keep chasing your tail.