Ground Cover North : Ground Cover 085 March-April 2010 - North
MARCH -- APRIL 2010 GROUND COVER Moisture management 11 Tight water use sets up long-term prospects SNAPSHOT Merced Farming Location: Wee Waa, north-western NSW Farm size: 2000 hectares irrigated and 300ha dryland, with a cattle and Merino enterprise at Ben Lomond, New England, NSW Soil type: Black self-mulching Average rainfall: 550 millimetres Enterprise: irrigated and dryland cotton, cereals, maize and legumes Average yields: mungbeans 1.8t/ha Sowing equipment: two homemade eight-metre-wide airseeders fitted with disc openers and Simplicity air carts Boomspray: Alpha Hardy Spray Rig with 24m-width boom Wee Waa irrigated and dryland grower James Kahl is optimistic water allocations will return, but in the meantime is concentrating on fine-tuning his farming system and infrastructure. PHOTOS: KELLIE PENFOLD Cotton emerging in remnant stubble from wheat, sorghum and mungbean crops on James Kahl's property at Wee Waa, in north-west NSW. While a lack of water for irrigated crops tends to be a 'negative', one Wee Waa cotton and grain grower is finding there can also be benefits BY KELLIE PENFOLD n For decades in north-western NSW's Namoi Valley the name Kahl meant cotton. James Kahl's father, Paul, was a pioneer of Australian cotton growing. However, after a run of dry years, James says he is now a moisture farmer and he grows crops according to the natural or irrigated water available. Sometimes it is still cotton, but it has been cereals and legumes that have helped him to at least break even while positioning the family's business, Merced Farming, to take advantage of any future increases in water allocations from the water use efficiency (WUE) gains made in the meantime. "We haven't slowed down at all. I've looked upon this period as a chance to better our systems by rebuilding our water-management facilities, trying new crops and varieties and fine-tuning the rotation to produce three profitable crops in any two-year period," James says. James is the family-owned enterprise's general manager, while his brother Robert runs the machinery contracting arm of the business and his brother-in-law Bruce Coppock manages the livestock. Twelve people are employed full-time in the business. In 2008-09 Merced Farming grew 250 hectares of cotton -- just over 10 per cent of its traditional total cotton plantings. The key driver for change has been the inability to plan because of unknown water allocations. James has established a paddock management program where all paddocks are easily adapted to any irrigated or dryland crop, with the changing of spacings on seeding implements becoming the main variable. Cotton, corn and soybeans are all sown on one-metre row spacings, whereas six rows of cereals are sown on each two- metre bed and five rows of legumes. Tractors are on two-metre wheel spacings, while harvesters are on four-metre. The arrival of two new varieties has also had an impact on the farming system -- Roundup Ready® Flex Cotton and CrystalA mungbeans. Roundup Ready® Flex Cotton presented opportunities for tighter rotations by allowing in-crop herbicide application and no pre- sowing tillage or after-sowing herbicide applications. It means cotton can, if necessary, be sown into a wheat stubble the day after the winter wheat crop is harvested. The rotation James feels works best is irrigated cotton, followed by winter wheat -- grown dryland but potentially irrigated if allocations allow for one or two waterings -- with mungbeans grown as a summer crop, with one watering followed by a winter fallow period, and cotton sown in the following spring. James first tried White Gold mungbeans and found that while the quality was reasonable, a newer variety, CrystalA, which he first planted in 2008, outperformed in germination, plant uniformity, colour, vigour, yield and quality. His work trialling irrigation impacts on mungbeans was recognised last year when he was named NW Plains finalist in the 2008-09 Excellence in Mungbean Production Awards. James compared one, two and three irrigations on mungbeans and found the best return -- 2.08t/ha -- was from one irrigation immediately before flowering on plants that were sown into good soil moisture. "The key to introducing a new crop to your system is whether the agronomics allow it to fit in easily and the CrystalA mungbeans offer advantages while producing a better quality bean than older varieties," he says. It also allows James to potentially lift soil fertility through nitrogen gain from the bean crop. The addition of new crops and cotton varieties and rotations has seen primary soil tillage reduced to once every three or four years -- or every fourth, fifth or sixth crop. "We used to deep till the paddock every second year for cotton and it was allowing moisture to just blow away," he says. "The other point is that when fertiliser prices sky-rocketed we decided we weren't going to use any and I think mungbeans helped keep our yields up in other crops." All crops are sown with a seeding unit that comprises a homemade tool bar fitted with disc-opener units and a Simplicity airseeder unit. James designed and built the unit after deciding that commercial seeders were "heavy and monstrous" and likely to cause too much compaction on the soft soils. □ More information: James Kahl, 02 6795 3777, email@example.com "In the 1990s we could grow cotton every summer, and plan three years ahead. Now we are lucky to be able to plan two months ahead ... and I have to say I am sick to death of it," James says. "I've tried to look for opportunities so that we are ready to go when this drought breaks." James says he no longer applies water with the aim of getting the highest yields. The focus instead is on the best WUE, rather than being a "petrol-head grower" -- just trying to grow the highest yields of everything without considering the gross margins or the water used. When there was not enough water for cotton, he explored growing 6.5-tonne-a-hectare irrigated wheat crops using 2.25 megalitres/ha, but then reasoned that if 1ML/ha produced 5t/ha he was better off spreading the water over more hectares. Growing 2.25 times the area of grain meant harvesting 12t per 2.25ML. "We've also learnt through better stubble management and creating ground cover that the soil is built up, so we can store more natural rainfall to put into crop yield." The paddock layout is based on eight-metre passes of the airseeder, planter or harvester and comprising two-metre beds. The sowing configuration is adjusted according to the crop choice and whether it will be irrigated.
Ground Cover 084 January-February 2010 - North
Ground Cover 086 May-June 2010 - North