Lessons from the drought

Name: Sheridan Alm and husband Craig
Current job title, winery & region: Best Vineyards near Moorook.

By Sonya Logan

This article first appeared in the January/February 2009 issue of Australian Viticulture.

If there was one thing that left a sour taste in Sheridan Alm's mouth following the 2008 vintage, it was paying between $800-$1100/ML for two lots of temporary water in September 2007 to irrigate her Riverland vineyards when the market peaked following the SA Government's announcement that allocations were unlikely to rise beyond 16%.

'We bought (water) in early September and again in late September,' she recalls. 'We honestly thought we wouldn't get more than 16% (allocation) let alone 32% and we could see prices (for temporary water) going up and up. Originally, we planned not to buy any water until December so we probably should have stuck to that plan but we very much felt like the Murray Darling system would run out of water.'

So the saying goes, once bitten, twice shy. Determined not to be caught out this season, Sheridan and husband Craig took advantage of a drop in temporary water early in 2008.

'There was no way that I was ever going to pay the sort of money we paid in 2007 again so we bought all that we needed in February and March. When we saw the price (of temporary water) drop to $200-$300/ML we decided we just had to buy some. This was a bit of a speculative move because carryover for 2008-09 hadn't been announced but I think this is something that growers are going to have to start doing more of - taking advantage of the low spots in the market whether they need the water then and there or not.

'We went into 2008-09 with the belief that we'd be lucky to get a 20% allocation. We wanted to start the season knowing that we had water in the bank. And having paid a sixth of the price for it makes me feel a lot better! 'It has left us a bit short of money for growing costs but banks are being very helpful at the moment in viewing temporary water as a temporary asset on balance sheets. 'Should we get allocated more water (than we've planned for) during the 2008-09 season we'll either trade the temporary water or utilise it for carryover for the next year,' she said.

Sheridan Alm is the director and manager of Yatco Pty Ltd, a business that manages family and investor-owned winegrape and citrus plantings. There are three family vineyards in the mix, including Best Vineyards, located approximately 2km north of the township of Moorook and owned by Sheridan and Craig, her parents and a handful of investors. Bought in 2003 and featuring light sandy clay loams and some Blanchetown clay layers in the middle of the vineyard, it contains 42ha of three to 50-year-old vines comprising Chardonnay, Shiraz, Cabernet Sauvignon, Sangiovese and Gordo, with Chardonnay making up 70% of the block.

Best Vineyards is entirely dependent on Wachtels Lagoon for irrigation water, a River Murray backwater downstream from Moorook, from which it has access to 375ML a year assuming a 100% allocation. Sheridan says the security of the water from the backwater is not as good as that direct from the river as the weir pool level has been difficult to maintain during low flow years.

Salinity has also become an emerging issue in the backwater during recent times. In the first week of January 2008, the weir pool level dropped and salinity readings conversely shot up, lingering between 1800-2500EC for three months. Unable to cease irrigating Bests Vineyards due to the prevailing heat and the irrigation regime on the property at that time of year which has it run in three six-hour shifts daily, the decision was made to increase each shift by two hours to counter the rising salinity.

'When the spike in salinity levels occurred in mid-late January, we wanted to make sure we didn't lost the crop so we deliberately applied extra water,' Sheridan explains. 'We aimed for a leaching fraction of 25%, rather than the 15% we'd applied in previous seasons. If we hadn't bought water (in September) we wouldn't have been able to do that with confidence.'

Soil salinity tests performed in mid-2008 revealed much lower levels than the year before - down to below 1dS/m in the top layer of soil with 3dS/m at depth the highest reading. Recent petiole test results in November have showed even further improvements on previous years. Sheridan says these results have taught her and Craig the benefits of putting on 'that little bit extra water on'.

At the time of purchase, Best Vineyards had a poorly-maintained overhead sprinkler system. That same year, a water restriction of 65% was announced at the start of the season, leaving the Alms feeling they had little choice but to begin converting over to drippers to get through the season.

'The efficiency gains from converting to drip was money well spent even though a 100% allocation was ultimately announced,' Sheridan recalls.

With the conversion to drip, the Alms decided to progressively reduce their use of water.

'During the first year of conversion, we put on about 6.5ML/ha on the Chardonnay. We still had some undervine sprinklers which were putting on around 7.5ML/ha. The next year we used drip only and our water use dropped to 5.5ML on Chardonnay.

'We got our water use down to an average of 3.8ML/ha in 2006-07 season but we now believe that is too lean given the drop in yields from that year - probably due to the amount of salt in the water as well as the amount of water used,' Sheridan says.

'We had significant fallout in yields, especially Chardonnay. Up until 2006-07 season, we'd been able to maintain big yields and consistent quality. We pushed things a little too hard during that season, especially when our allocation got cut back from 80% to 60%. So, in 2007-08, we decided that Chardonnay especially needed more water than we'd previously been applying. We then became aware of the salinity issue which made the decision even more important.
'In 2007-08 we applied on average 5.7ML/ha - Chardonnay 6ML/ha and other varieties 5-5.5ML/ha. Some growers may be able to lower their water use to below that, but I'm not sure that's possible here due to salinity.'

In 2007-08, as with all their properties, the Alms resolved to water all the vines in their three vineyards, including Best, with the aim of producing a viable commercial crop and achieving similar quality as previous years, rather than just simply keep them alive.

'We did some numbers prior to the start of the season - some 'what ifs' - which indicated that as long as we could see our way through the lending situation in the short term, buying in water was the better option. The consequences of not buying in water was worse than having a financial loss, not to mention the consequences of waiting for yields to return to normal,' Sheridan says.

The 32% allocation that prevailed in 2007-08 gave the Alms access to 120ML to irrigate Best Vineyards, as well as 10ML of carryover.

'We leased in 135ML and planned to put on 240ML and we did,' Sheridan says. 'A big decisions we made was to let 25% of the vineyard go to ensure we had enough water to look after rest. Although the vines we let go had been paying their way, we didn't believe they would continue to be profitable, especially given the prospect of having to lease water in coming years. The varieties we let go were Chardonnay, Colombard, Malbec, Merlot, Crouchen, Cabernet Sauvignon and Tokay. But, the decision to let them go was based more on the health and age of the vines than the varieties themselves, these areas had been part of a longer term redevelopment plan which was in effect brought forward.'

Sheridan says that although Best Vineyards did not break even in 2007-08, by letting some plantings go its grapegrowing costs were greatly reduced. 'It's quite feasible that with average yields we could have broken even. Red varieties yielded 17-20t/ha in 2007-08, Chardonnay averaged 12t/ha. Previously, we've averaged 25t/ha easily,' she notes.

The Alms initially intended to redevelop the vines they've abandoned at Best Vineyards right away, but the need to spend money on water has meant those plans are on hold. When circumstances eventually enable the redevelopment of Best Vineyards to go ahead, the Alms will ensure that all new plantings are on rootstocks. Although most of the current plantings in all three vineyards are own-rooted, there has been a noticeable difference between their performance under the reduced water regime that has prevailed during the last two seasons compared with the few that are on rootstocks, which are mostly Ramsay.

'The vines on rootstocks realised higher cropping levels and the vines looked better at the end of the season compared with the vines on own roots. The cane thickness and size of leaves was also quite different. We had a bit of trouble with RSG and frost in the last two years and the vines on rootstocks seemed to bounce back from that a lot better.
'Any future plantings we do will only be on rootstocks. At Best Vineyards in particular the vines on Ramsey rootstocks seemed to handle the salinity issues experienced in 2007-08 better. We would have planted Ramsay a lot earlier had the wineries viewed their use more positively, ' Sheridan tells.

For the first time last season, polymers were applied via drip irrigation throughout Best Vineyards over three applications which Sheridan says have made a positive impact.

'Although we didn't do any trials, the polymers seemed to allow more reaction time in our irrigation scheduling. While we weren't aiming to use less water because we wanted to make sure we were pushing salt through the rootzone and get some vine health back into our Chardonnay, we did notice that the soil profile didn't dry out as quickly and probably stayed wetter at depth for longer. Although it doesn't sound like much, a day extra a week in your reaction time with your irrigation scheduling makes a big difference and that might result in using less water.'

To assist in monitoring soil moisture levels in Best Vineyards and their other vineyard further up the river near New Residence, the Alms have been using a Diviner 'A Diviner is a really cost-effective tool,' Sheridan remarks. 'You can pull up graphs on a computer and see what's happening - with drip irrigation it's a very handy safeguard. But, through experience, we know that during the peak of the season, the irrigation systems at Best and Litchfield need to run 24/7. Because there's not a lot of give in the schedule we probably wouldn't put off irrigating for a day even if Diviner readings said we could because experience has shown that we would probably end up being behind because of the nature of drip. You can get caught out badly with drip, especially during a heatwave.'

The Alms are also in the process of establishing several Sentek SoluSampler sites at Best Vineyards to help with monitoring rootzone salinity. 'We're hoping they might also lead to efficiency improvements in fertigation too,' Sheridan adds.

A cover crop was sown for the first time in the vineyard this year, primarily in an attempt to control couch, but has also been useful as a mulch once sprayed out in spring to avoid competing with the vines for water. A mulch of grape marc has also been utilised this season.

'We've used grape marc previously on young plantings as a mulch and intended to eventually apply it to all blocks however reductions in profitability in the two seasons and availability of grapemarc had put those plans on hold. This year we've put it on everything; at 30t/ha it's not a thick layer, perhaps a couple of centimetres. We are aiming for a thicker layer over time, hopefully it will just be a matter of topping it up each year.

'Grape marc has been recommended as a good agent for offsetting sodium in saline water due to its high potassium content. Coming into the season we did not know if salinity was going to be an issue at Best Vineyards this year but even if it's not the grape marc will be ok as a mulch anyway.

'We will also continue to apply calcium nitrate through the fertigation system at Best Vineyards this year to help counter the salinity issue.

'We've also shifted from using commercial fertilisers to a mix of organic and man-made fertilisers because of cost. We would like to have used a lot more organic fertilisers before now but until recently the cost has been skewed in favour of synthetics but now they're quite comparable. We believe the enhanced organics in the soil will also lead to water-use efficiency gains,' Sheridan says.

The Alms are also progressing their use of the Irrigation Recording and Evaluation System, or IRES, which allows irrigators to keep comprehensive irrigation records which can be analysed to evaluate water use efficiency down to the irrigation valve unit level. Developed by Rural Solutions SA, IRES produces comprehensive irrigation reports in table and graph formats for specific crop types, varieties or rootstocks.

'It's a time-consuming tool to begin with but we can see the value in it. IRES can give a more accurate figure on water-use efficiency on a daily basis rather than simply relying on meter readings after every irrigation alone. We are still learning how to use the system completely but believe it will be a valuable planning and post irrigation assessment tool to assist with scheduling and monthly budgeting.'

For the 2008-09 season, the Alms have budgeted on using the same amount of water they did at Best Vineyards during the previous season.

'If anything, we've budgeted a bit extra in case high salinity levels are recorded across the entire season not just a couple of months - we could envisage using up to 6.5ML/ha at BestVineyards under those circumstances. During this season to date salinity levels at Wachtels Lagoon have remained below 1000 Ec units but as the weather warms up now we will be closely monitoring their levels for any upward movement. We have applied for Critical Water Allocation which should give us further confidence going into next season as will the very recent announcement of another Carryover Water scheme for River Murray Irrigators. The stable market price of temporary water allows even greater flexibility in planning for the 2010 season.

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