Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 447 IREC Farmers' Newsletter No. 197 — Autumn 2017 The aim of this three-year project is to provide growers with strategies to confidently schedule irrigations to optimise water use and yield of cotton crops. The project is investigating a plant-based irrigation scheduling method that uses continuous measurement of canopy temperature to monitor water stress in cotton. Using a plant-based method is advantageous as plants respond to both their soil and aerial environment. Using canopy temperature sensors means the information is not dependent on the influence of different soils or soil structures. Results from previous project sites across NSW and Queensland since 2008 show a strong correlation between cotton yield and canopy temperature. This research is working towards using canopy temperature sensors in water-limited situations. Optimised row configuration One highlight of the tour was attending the Gwydir Valley Irrigators Association annual research field day. One of the project sites visited as part of the field day was the Optimised Row Configuration trial at Auscott Midkin. This is an extension to a trial conducted over the 2014–15 and 2015–16 seasons. The trial is investigating the relative yield potential and water use efficiency of three row configurations: 30 inch, 40 inch and 60 inch. The researchers have found that establishment in 60-inch rows is more difficult than in narrower rows, as getting water to the centre of the beds is problematic. The 60-inch row spacing is more advantageous in water-limited years and has good water use efficiency. Along with the 30-inch spacing, the 60-inch spacing has the added advantage of fitting in with the three-metre wheel spacing typical of broadacre farming in the region. In abundant water situations, the narrower row spacings (30 and 40 inches) have a more consistent water use efficiency and much better yields than the 60-inch spacing, with 40 inch yielding 15 bales/ha while 60 inch yielded 13.3 bales/ha, in the 2015–16 season. Automated siphons The second site of the GVIA field day was Red Mill to see how Islex Smart Siphons work as part of the Investigation of Siphon Automation Options project. This system of siphon management is new technology that has great potential to save labour. At Red Mill the Islex Smart Siphon system has a 75 mm straight pipe drilled through the supply channel bank to feed a furrow. Up to 100–150 pipes are linked by a cable back to the winch controller. At the supply end of the siphon there is a 90 degree elbow with a riser pipe. To start the flow the Smart Siphon rotates at the elbow, lowering the pipe end into the water. To stop the flow a winch controller rotates the elbow to raise the pipe out of the water. The main issues with this system have been trash getting caught in the elbow and the rota bucks being eroded away after a few irrigations due to the velocity of the water. A new prototype has been designed to address the issues identified this season. Both the optimised row configuration and automated siphons projects, as well as the GVIA annual research field day, are funded through the Smarter Irrigation for Profit project (under Rural R&D for Profit program) and the Cotton Research and Development Corporation. Broadacre nuts The next stop of the tour was to the impressive pecan farm of Trawalla, where the 20-metre tall pecan trees provided a cool reprieve from the scorching Moree heat. Trawalla is the flagship property for the operations of Stahmann Farms. The 700-hectare pecan orchard east of Moree was started by Deane Research in the Gwydir Valley comparing row configurations of 30, 40 and 60 inches for cotton production. Siphon automation is being investigated at Red Mill to determine benefits of labour saving and to see if water efficiency is maintained or even improved. Stahmann Jnr not long after he came to Australia from the United States in 1965. Deane found the varieties of Wichita and Western Schley produced the best yields and quality. Cross-pollinating rows are planted throughout the orchard, which has 10x10 m plant spacing. Flowering occurs in September, with nuts fully formed by February. The whole orchard was originally set up to be flood irrigated down the inter-row, with water use at 10–12 ML/ha. Over the past few years, the team at Stahmann Farms has been working to convert the farm to subsurface drip irrigation (two drip lines per row at 20–30 cm deep), and 40% of the farm is converted so far. This has seen water use fall to 5–6 ML/ha. Stahmann Farms wants to keep trees at a height of 12–20 m and to achieve this they have a pruning rotation, where trees will be pruned on one side every year. This way, the trees will not suffer a yield decrease. Across the river the company's new property has 120 ha of pecans planted at 10x5 m spacing. At this narrower plant spacing, trees will be kept to 8 m tall. A further 140 ha will be planted this coming autumn. Pecans are biennial yielders, so yield varies from year to year. In the off-year Stahmann Farms harvests between 1500 and 1700 tonnes of nuts, this increases to 2200–2500 tonnes in the on-year.