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© Kondinin Group Cropping Grain storage This article has been reproduced with permission from Farming Ahead. For more information about Kondinin Group phone 1800 677 761. Further duplication of this article is not permitted. Popularity of harvest bags heating up Grain harvest bags are gaining global popularity as a low-cost, temporary storage system for maintaining grain condition for many months post-harvest. At a glance • Grain harvest bags are low-cost grain storage units used to store harvested grains safely, allowing growers to better manage and market their crop. • Each bag can store up to 300 tonnes of grain in an airtight environment which also provides protection from pests. • Grain storage bags in Australia might enable ripe crops to be harvested at higher moisture contents, increasing harvest flexibility and overall productivity. G rain harvest bags are an increasingly popular way for growers to capture, control and conserve the maximum value of a crop. The bags are low-cost membrane-based grain storage units which allow growers to by accelerate the production of carbon dioxide and depletion of oxygen. These conditions suppress the activity of any fungi or insects present, preserving the grain in its original condition. Louise Lawrence and Len Caddick, CSIRO ENTOMOLOGY store grain on-farm, bypassing expensive contract transport and enabling the rapid harvest of a ripe crop at its maximum value. The bags can be used to store early harvested grains safely and to segregate grain into small, identifiable batches, allowing growers to better manage and market crops. Harvest bags are an effective and economical alternative to permanent, expensive on-farm storage and can also facilitate the use of contract harvesting, especially when on-farm storage and transport are limited. World trends In Argentina, where permanent storage is in short supply, the use of grain harvest bags has increased rapidly. During 2004, grain bags were used to store more than 18 million tonnes of Argentinean grain, including wheat, maize (corn) and soybean. The bags are also becoming popular in other Latin American countries and in South Africa, where they provide an economical system for short- and long-term grain storage. The rate of adoption on farms is a reflection of the success of this technology in maintaining grain quality to required marketing specifications. The triple-layered polyethylene bags have largely been developed in Argentina, where similar plastic bags have a long history of use to store silage. Argentina has also developed machinery for handling harvest bags. Harvest bags have been used in Australia for several years, but the limits of this In the bag Harvest bags produce an airtight environment and under favourable conditions grain is protected against insect pests without the use of pesticides. Each bag is seamless and holds up to 300 tonnes of grain. After the two ends of the bag are sealed, the moisture content and temperature of the enclosed grain interact to Grower reaps $30,000 saving by using harvest bags Farm information Using grain harvest bags instead of buying 10 new silos saved Victorian mixed farmers, the Nicholson family, more than $30,000 during 2005. Farmers by Megan Broad, for CSIRO ENTOMOLOGY Location Campbell's Bridge, Victoria Property size 1360ha (90% arable) Enterprises Cropping and sheep Annual rainfall 400–475mm Soil type Grey clay to light sandy loams Soil pH 5.6–6.8 (calcium chloride) 48 S avings of $30,000 and the opportunity to store grain to sell during market peaks prompted Campbell’s Bridge, Victorian growers, the Nicholson family, to try grain harvest bags. Robert Nicholson Robert, Lorraine and Scott Nicholson Robert, Lorraine and Scott Nicholson, Campbell’s Bridge, Victoria, believe they will be ahead in cost savings with harvest bags as the bags do not require fumigation like silos. Robert Nicholson decided to try the grain harvest bags during 2005 to store 750 tonnes of his noodle wheat, oats and barley to provide more marketing flexibility. One option to store the grain was to buy 10 new 75t silos, worth more than $80,000. Rather than selling the grain as it was harvested at the lowest point of the market, Robert wanted to store the grain to generate more profit per tonne from pre- and postharvest sales. Instead, Robert bought a machine to fill the grain harvest bags for $17,000 and four 75-metre long bags at a cost of $15.50/m (about $4/t wheat stored). At the time of publishing he was unsure whether he was FA R M I N G A H E A D No. 171 April 2006 technology under Australian conditions have yet to be determined. Typically, Australian grain is harvested drier than in Argentina, which could be an important factor in determining the performance of storage bag technology, since dry grain is unlikely to have sufficient fungal or respiratory activity to generate the advantageous low-oxygen, high carbon dioxide environment. Further, although the grain might still store well in this situation, there is a chance that the bags might not develop an insecticidal environment, and that moisture movement in the bags could lead to localised moulding. Technology trial Researchers from CSIRO Entomology will study harvest bags to determine their effectiveness in Australian conditions. Trials will determine whether silo bag technology offers growers significant advantages over traditional storage methods and whether using this technology under Australian conditions might expose the grower to unexpected risk. The study will include research into the possible loss of processing and end-user quality, as well as the overall cost and logistics associated with grain bag use. The trials will track the quality of wheat stored in grain bags in a paddock for up to 12 months. A grain sample and profile will be taken for each bag during filling and out-turn going to use a contractor or buy a machine to empty the bags, for an estimated cost of $25,000. Either way, Robert believes he will still be ahead in costs savings, especially as the bags do not require fumigation unlike silos. Although he acknowledged the cost of replacing the bags each year, Robert maintained the increased market flexibility, storage flexibility and minimal maintenance made the option more viable to him than silos. Filling the bags The process of filling the bags was straightforward and efficient. A total of 250t of wheat, 200t of barley and 300t of oats was put into four bags. One wheat bag held grain from two different paddocks, which yielded different protein levels, separated by a line drawn on the bag to define the change of grains. Robert maintains even if he loses 1t of grain from the grain mixed at the separated line, the loss will be insignificant compared with mixing the two grains in a silo and effectively reducing its value and FA R M I N G A H E A D No. 171 April 2006 Cropping Neil McAlpine Grain storage During 2004, Argentinean farmers used harvest bags to store more than 18 million tonnes of wheat, maize and soybean. If used in Australia, the bags might allow harvest of ripe crops at higher moisture contents. and probe samples also will be taken during storage. Unpowered sensors in the bags will take temperature and relative humidity measurements to determine any risks to the grain. Oxygen and carbon dioxide levels also will be monitored closely to assess whether an airtight environment is achieved. The results will help determine whether the bags will enable harvest at higher moisture contents, since the ability to harvest ripe crops wetter can increase harvest market opportunities. The massive plastic bags are delivered folded into a large cylinder and are winched over the machine. One end of the bag is sealed and the Nicholsons used a chaser bin to auger the grain into the bagging machine. Bag durability Robert’s main concern about the bags is how they will withstand white cockatoos as he has already found one or two holes in the bags. He does not believe Australia’s harsh climate will be a problem, provided the grain is emptied within 12 months, although he does have reservations about how it will withstand a hailstorm. Grain quality Robert is keen to find out if there is any impact on the quality of grain from the bags as maltsters reputedly have concerns about moulding from harvest bags and any deterioration would reduce the system’s appeal by reducing marketing options. The Nicholson family also leases some country and sees potential to use the bags on grain harvested there, rather than transporting it back to the main property. flexibility, reduce weather damage and increase overall productivity. The study, funded by the Grains Research and Development Corporation, will start with an extensive survey of growers already using the technology to assess the current performance of the bags, highlight the advantages of their use and document any problems encountered with loading and out-turn and during storage. For more information contact Len Caddick, CSIRO Entomology, on [email protected] or phone (02) 6246 4214. At a glance • Compared with buying new silos, adopting the harvest bag system saved $30,000 for Victorian mixed farmers Robert, Lorraine and Scott Nicholson. • Grain in the harvest bags can be sold during price peaks rather than during grain gluts. • Different grains can share a bag with only small losses from grain mixing. • The Nicholsons have some concerns about potential damage to the bags from white cockatoos and hailstorms. For more information contact Robert Nicholson on email [email protected] or phone (03) 5359 0218. 49