Ground Cover North : Ground Cover 074 May-June 2008 - North
Yield push puts holiday on hold Simon and Bill Tiller have found that their work after harvest, improving soil quality and managing summer weeds, has the biggest effect on their enterprise's profitability n Despite the surf being just 40 kilometres away, growers Simon and Bill Tiller, at Esperance, WA, eschewed their usual summer respite this year, returning instead to the tractor cab to carry out what they now consider the two most crucial jobs to lift yields on their 8000-hectare property. Simon and Bill, a father-and-son team who run the farm with their wives Felicity and Rose, moved to the region eight years ago from an 800ha sheep and grain property at Balaklava in South Australia. They have found that the work they do straight after harvest to improve soil quality and manage summer weeds has the greatest impact on the enterprise's profitability. "The tractor hours we put in last summer were huge," Simon says. "But there is no greater feeling than sitting in a header at harvest and seeing a crop that is yielding so much more as a result of the effort you put in before you even planted it." When the family took over the farm, salinity and poor soil quality appeared to be the two biggest deterrents to lifting production. More than 70 per cent of the land was non-wetting sand over clay, which generally sheds moisture quickly, allowing water to gather in hollows and, over the long term, results in saline soils. "It created a lot of headaches. One year we planted 16,000 trees and fenced off areas that were too saline, but we wanted to avoid further salinity. About 30 per cent of the farm, at that stage, was affected by problems caused by non-wetting soils," Simon says. Clay spreading had been a popular technique for soil improvement in the district, and with such a large area to be improved -- some 1800ha -- the Tillers researched clay delving: "Initially we used our own carry grader to do clay spreading on 240ha and that worked well." After finding there were very few large- scale clay delvers on the market -- with two tynes at the back and two at the front, instead of the usual one at the front and one at the back -- they designed and built their own 18-tonne delver in their workshop. In 2006, they had an EM38 survey carried out of the affected areas to measure the depth of the clay over the paddocks, with the results then loaded into their tractor's GPS. "First, we would look at the maps on our laptop and then work with the GPS, which showed us the real-time depth of the clay, to establish which area needed to be clay spread and which area needed delving. Where the shallowest clay was we would dig a pit and use that clay for spreading the areas deeper than 600 millimetres and then wherever the clay was less than 600mm deep we would bring in the delver." After delving, an off-set disc went over the area three times to incorporate the clay and then the soil was smudged using two large pieces of railway line towed behind a tractor for five passes. With a total of eight passes, the cost of fuel and labour was $350/ha. In early 2006, the Tillers carried out clay delving on 500ha and another 500ha will be improved this year. "In the first season after delving, the yield increase, in a dry year, was up by 130 per cent in some areas," Simon says. "Before harvest 2006, in the affected area, we had never harvested a crop over 2t/ha, but in the worst drought in history we achieved 3.2t/ha. "Never before had we done something from which you could reap the benefits so quickly: an investment of $350/ha and we will gain from the results for another 30 years." But clay delving was only part of the extra tractor miles put in over summer. Weed spraying also kept them from the beach. In December 2006 they took delivery of a WeedSeeker® boomspray, which uses infrared sensors to identify and spray weeds. "I had a mate who went on a controlled- traffic-farming trip to NSW four years ago who saw one in action at the Brownhills' property at Spring Ridge and didn't stop talking about it. It got me thinking, and we heard they were bringing one over for a demo. I offered a paddock that we thought was covered in paddy melons, but the WeedSeeker® only sprayed seven per cent of the paddock and killed 99 per cent of the weeds. We couldn't believe it." The Tillers' herbicide bill was reduced from $45/ha to $30/ha, and Simon expects it to fall further as they refine the system. After 200mm of rain in December 2006, the farm was hit with three weed cycles, requiring three passes with the WeedSeeker®, as moisture moved through the soil. The payoff was apparent by late winter 2007, when the season again began to dry off. However, the effective weed kill meant most of the summer rain was retained in the soil and the crops held on. Simon is now confident that even if dry finishes become more common, the retention of early moisture will make the difference between an average and a good yield. Because the WeedSeeker® focuses on broadleaf weeds, the Tillers are planning a modification to the system to control small summer grasses and self-sown cereals. For 2008 they will move it from the self- propelled sprayer to a trailing boomspray with a twin tank, and two lines and pumps. The larger tank will be filled with a broad- spectrum chemical, such as Roundup®, which can be used at a lower rate for a general kill, while the small tank will be connected to the WeedSeeker® with more specialised herbicides, focusing on big weeds such as melons, radish and turnip. The aim is to spend less time revisiting paddocks. Simon says the 36.5-metre WeedSeeker® cost $180,000, but looks like paying for itself in two years: "We can achieve this because of scale, but even operators with smaller cropping programs would benefit ... an 18m WeedSeeker® is half the price and would be paid off at the same rate over 4000ha of crop, or the 9m unit over 2000ha of crop. "Before we had this, we felt a paddock of scattered second-germination weeds wouldn't be worth respraying. In hindsight, I think they are the weeds that cost you moisture and money." Working with an average rainfall of 400 to 450mm, the Tillers plant 2600ha of wheat (AnnuelloA and GBA SapphireA), 2600ha of barley (BaudinA and, this year, BulokeA), 1400ha of field peas (KaspaA) and 1400ha of canola (CBTM Boomer and CBTM Tanami). In the eight years at Esperance they have averaged 2.8t/ha for wheat, 2.6t/ha for barley, 1.6t/ha in field peas and 1t/ha for canola. "We like to work on a six-year rotation of wheat, barley, field peas, wheat, barley, canola because we get a good disease break every three years and opportunities to use other chemical groups every three years." The cropping system is described by the Tillers as being "minimal traffic on the way to controlled traffic". Working to a three- year plan, most of their machinery has been modified or bought for 3m tracks, with the 15.5m airseeder due to be replaced by a 24m bar to bring all the machinery into line. In 2008, Simon says row spacings may move out to 34cm, based on trials carried out this year. "We've been on 25cm spacings and (in 2007) tried 38cm in trials and I think that might be too wide. Visually, the crops look to benefit from the wider spacings in dry conditions, but with 38cm spaces we'd struggle to keep the ryegrass under control due to ineffective trifluralin incorporation." Five years ago the family invested in a GPS base station with 2cm repeatable accuracy and from this have moved into a program of controlled-traffic farming: "I think taking your time is the practical approach rather than trying to change all your gear over at once," Simon says. This year Simon and Bill have built a spray cart to be pulled behind the self-propelled windrower to spray-out ryegrass as canola is windrowed. "It's about eliminating seed numbers. If you leave the ryegrass until after harvest, it has usually set seed and will live through the Select herbicide it gets. It only takes another three applications of Select over six or nine years at this stage of seed set and you can have resistant ryegrass," he says. The spray cart has a 3800- litre tank, which will carry a cheaper herbicide, such as Roundup® or Gramoxone, enough to cover 76ha, meaning a refill every six hours. "Then we have plans to build a shielded sprayer for inter-row spraying of legumes ... there's always a project on the go." □ More information: Simon Tiller, 0429 787 012, firstname.lastname@example.org Simon Tiller adjusting his WeedSeeker® boomspray, which uses infrared sensors to identify and spray weeds. PHOTO: EVAN COLLIS On farm MAY -- JUNE 2008 GROUND COVER 4 BY KELLIE PENFOLD AFTER FINDING THERE WERE VERY FEW LARGE-SCALE CLAY DELVERS ON THE MARKET ... SIMON AND BILL TILLER DESIGNED AND BUILT THEIR OWN 18-TONNE DELVER IN THEIR WORKSHOP.
Ground Cover 073 March-April 2008 - North
Ground Cover 075 July-August 2008 - North