By Grant Rolston
Vineyard Manager, Vinewise Viticulture
Wow! Where did the last three seasons disappear to?
The focus vineyard project has been a great experience, and I am sure we have all learnt plenty from it.
We were fortunate here to have a warm dry autumn. Harvest went well with no real problems; we were a touch earlier than average. Fruit quality was good overall and we are looking forward to the wines that will result. We are quietly moving into pruning and so have time to reflect, not only on the season but on the project over the past three years.
What I would like to do here is give my overall view of our part of the project here at Gibbston Valley. I will do this purely from an observational point of view and not enter into technicalities, focusing on what I saw as some major points that we encountered, along with my thoughts about those.
The first part of conversion required some planning of how we would go about the task ahead. Probably the biggest consideration initially was how to deal with weeds; we chose undervine weeding with a Braun. This would require the first major financial input and so for us the major cost of conversion was accommodating this type of machinery. The costs came from the necessity of lifting the existing irrigation drip line up out of the way to a height of about 40cm. We also needed to stake any young vines as well as protect irrigation flush valves, solenoids, etc.
The weeding itself has gone pretty well. We were fortunate that the vineyard was well established, and therefore we have lost very few vines to mechanical damage. We did have more weed competition than we would have liked in one block in year two, and this showed in the lack of vigour in that block.
Timing is crucial with weeding. We used an outside contractor and so weeded when the gear was available. Ideally one would have the luxury of being able to choose those hot northwest windy days to carry out weeding operations. In saying that, we do get a lot of warm days, and generally we had good results. The Bendigo site is very dry, with little summer rain, and this certainly helps with weed control.
Nutrition was the other major consideration; looking back I think we could have given the vines more from the start. It can be a big change for the vines from a conventional state to one with a little more competition and alternative nutritional inputs. We definitely saw some vigour issues, particularly in year two, maybe a little shock. The vines were fine in year three, though we did have a great spring to help them on their way.
There are so many organic products available now that any nutritional issues can be dealt with. I take the view now that we probably need to give nutrition both through foliar applications and also via the soil, as well as fertigation if available, certainly in the initial years. I believe that once the vine roots explore further away from their previous nutritional source (the drippers), then they will find most of what they require if it is actually available in the soil.
Erosion was an initial concern, as the site lies on a reasonable slope, and we have very light soils. I am pleased to say that we have actually seen the reverse of what we may have expected. The conventional sites with the herbicide strip continue to erode, with little rivulets forming during rain events. These spread out into the wheel tracks and erode the soil, to the point where the gravels are exposed. In contrast, the organic blocks with the undervine weeding seem to soak up the rain and have little to no runoff.
Canopy management inputs were reduced in the organic blocks in some instances, due to the lower vigour giving a positive financial spinoff. Caution needs to prevail with regard to having sufficient canopy to successfully ripen the fruit.
Planting the interrow
Interrow cultivation was practised in every tenth row, with the idea of growing buckwheat and phacelia. We either plant early while we have moisture to get a strike, but then risk frost to the buckwheat in particular; or risk planting later. The issue with planting later is that typically the vineyard gets very dry and then we don’t get a strike anyway. We tried both early and late but neither did very well. We always had some success, just not as prolific as we would like.
We look forward now to the final phase of the project with wine comparisons being made and the report due out later in the year.
There have been some problems during the course of this journey, but none of them have been insurmountable. There is plenty of knowledge both within and supporting the industry; there are people out there willing to help, lend a hand or give advice. Importantly, there are people who will share their experiences. Often they faced the same problems, and the practical advice they can give is invaluable. If you are contemplating conversion seek out a friend or neighbour and you will be amazed at the help they can offer simply because they share your passion for organic production.
We are fortunate to have been involved with this project. It has required a lot of input from quite a few people and the time required to gather and record all the information has of course been necessary but also time-consuming. We have been able to make comparisons that would not have otherwise been made, we have seen consultants that we may not have otherwise seen, we have received advice and inputs not only from the experts but also importantly from others attending field days. While the technical information and advice is important, practical advice and application is huge. I take a moment to thank all those involved both in our team and across the country with the project as a whole. I especially want to thank those that turned up to our field days. It gave us encouragement, that so many were interested in what we were doing.