2013 Technical discussion haymaking technology

More than 50 participants were interested in haymaking technology during a technical discussion on this topic at the University of Kassel's experimental farm. It was organized by the Department of Agricultural Engineering at the Faculty of Organic Agricultural Sciences at the University of Kassel together with the KTBL.

Hay has always been a widely used feed for numerous animal species such as cattle, goats, sheep, pigs and small animals, but has recently been on the decline. Many farmers are increasingly turning to silage. The reason: silage can be brought in very quickly as it is ensiled with a moisture content of 60 percent to 65 percent. Hay may only be stored with a maximum moisture content of 13 percent in order to avoid quality losses due to mold or the dreaded spontaneous combustion.

More than half of the participants were practitioners who primarily need hay for their own cheese production and to supplement their rations when feeding. However, they also appreciate that hay can contribute to high milk yields from the basic feed and to very good animal health and thus high lifetime performance. In addition, the need for concentrated feed is minimized. The contribution by Bioland farmer Josef Braun from Freising inspired the audience: He achieves an average milk yield of 6,000 - 6,800 liters per year with high-quality hay from species-rich arable forage farming with a lifetime yield of 8-9 years without concentrates. He needs the hay to feed his 24 dairy cows, whose milk is cheesed and marketed directly. When preparing the hay, he drives the hay with a moisture content of 45% into the drying box with the loader wagon and dries it down to a water content of 8% in three to five days. To heat the drying air, he uses ventilation from the 90 kW photovoltaic system on the drying barn. A fan blows the warm air from the roof area through the hay barn. A full cost calculation as part of a bachelor's thesis at the Technical University of Munich showed that the system with a double-skin roof was very economically viable.

Björn Bohne from the Department of Agricultural Engineering presented initial results from his investigations in the project "Improvement of haymaking technology", a joint project of the University of Kassel and the Board of Trustees for Technology and Construction in Agriculture (KTBL), which is funded by the Federal Ministry of Food, Agriculture and Consumer Protection (BMELV) with around 300,000 euros.

The main aim of the project is to define the requirements for suitable advertising and harvesting technology for leafy hay, especially alfalfa hay. An important parameter for the assessment is the losses incurred during haymaking, which are essentially made up of respiration and crumbling losses. If these losses are now allocated to the respective process step in haymaking, this results in a value of 2.2 to 4.4 % for mowing, 6 to 20 % for tedding, turning and swathing and 4.4 to 11 % for baling. Advertising therefore plays a key role when it comes to minimizing crumbling losses. Consequently, the first year of the trial focused on crumble losses during haymaking. The first step was to optimize the methodology for recording crumbling losses. Intensive further development of the methodology resulted in better reproducibility. The innovative "broom method" proved to be particularly suitable.

The shape of the swath has a significant influence on the density distribution in the round bale: the swath therefore also determines the drying properties of the bales on an aeration system. In the 2013 trial year, the focus was therefore on haymaking, particularly swathing. Hay harvesting and aeration will be added in 2014.

The sales manager for Germany, Heinrich Bührke, from the Finnish agricultural machinery manufacturer ELHO, presented its special swath fan and swathing technology: Both technologies have proven themselves in Finland in hay and straw harvesting for years, as they stand for low losses and high hygiene quality. Contamination is also minimized on areas fertilized with manure, as the forage has little contact with the ground during turning and raking. Of particular interest here is the drum rake technology, which was widely used in Germany in the 1950s as a push rake tedder. A major problem at that time was the dreaded drum wrappers, whereby long hay wrapped around the turning drums. Today, this is no longer an issue thanks to the installation of scrapers and the use of improved tines. The hydraulic drive makes it easy to change the drum speed, which is very helpful for adapting to different operating conditions. In particular, the airy swath with good side filling makes the drum rake, which belongs to the medium rake group, a good partner to the round baler.

Peter Weinand, Head of the Forage Harvesting Division at the German agricultural machinery manufacturer CLAAS, presented the latest forage harvesting technology and impressed the audience with his technical innovations. He covered everything from mowing technology to loader wagon and baler technology and emphasized the correct machine settings as the greatest potential for reducing forage losses. CLAAS still has considerable potential in the field of haymaking technology: Improvements should be made in operational safety, efficiency, protection of the forage and sward, drying time, degree of contamination and forage losses. CLAAS has already launched a number of innovations to achieve these goals, for example the optimum contact pressure of the "Active Float" mower and the higher pick-up capacity of the "Max Spread" tedder. Other sensors and systems for moisture measurement and automatic machine control will come onto the market in the next few years.

Jochen Burmester from the DLG Test Center for Technology and Equipment in Groß-Umstadt explained in detail the various test procedures and measurement technology used by the DLG. He presented both the test portfolio for crop production technology and explicitly the methods used in grassland harvesting technology. Here, the drying process, lateral distribution, swath profiles and raking losses are determined, as are bale weight, bale density and power requirements. These results are then incorporated into the various DLG test marks, e.g. the DLG focus test, which supports the farmer when purchasing machinery.

Alfred Pöllinger from the LFZ Raumberg-Gumpenstein focused on gentle hay drying. He explained the application limits of hay drying and presented various system solutions. He focused in particular on structural and technical implementation details. In his view, round bale drying has a number of important advantages, as this technology is well known in practice and can be successfully implemented in terms of labor efficiency. The storage space required is practically 20 % less and the bales are easy to handle. However, round bale hay is also particularly susceptible to mold and the air flow in the bales is already determined during baling. The capacity of these systems is generally lower than that of drying systems for loose green fodder. He described the application limit of a round bale aeration system as a water content of 30 %. He also discussed key figures for intake and crumbling losses and their determination. He also named a bale density of 130 kg DM/m³, a bale diameter of 1.50 m in double rows or double-deck drying, a pressure-stable blower with frequency converter and the heating of the drying air as important prerequisites for a functioning round bale aeration system. This can be done using the waste heat from a biogas plant or by heating wood to a maximum of 50°C using solar under-roof extraction. The use of a dehumidifier can speed up the drying process.

Susanne Jakschitz-Wild from the State Institute for Agriculture in Freising gave a very clear and well-founded presentation of many practical examples of drying loose hay and round bales. She is currently working on the creation of a database on hay ventilation in Bavaria in which operating parameters will also be recorded, which should ultimately lead to recommendations for settings.

At the end of the event, there was still the opportunity to discuss topics in more detail, which was also actively used. Björn Bohne thanked the speakers and participants and asked the participants to leave their contact details if they were interested in the project in order to possibly participate as a test farm in the coming years.

Press release 04.12.2013 An underestimated feedstuff: Expert discussion in Frankenhausen on modern haymaking techniques