2013 Technical discussion haymaking technology

More than 50 participants were interested in the technology of hay preparation during a technical discussion on this topic at the experimental farm of the University of Kassel. 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 been on the decline in recent times. Many farmers are increasingly turning to silage. The reason: silage can be brought in very quickly because it is ensiled with a moisture content of 60 percent to 65 percent. Hay may be stored at a maximum moisture content of 13 percent 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 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 of the 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 concentrated feed applications. He needs the hay to feed his 24 dairy cows, whose milk is processed and marketed directly. When he prepares the hay, he drives the loading wagon into the drying box while it still has a moisture content of 45% and dries it down to a water content of 8% in three to five days. To heat the drying air, he uses rear ventilation from the 90 kW photovoltaic system on the drying barn. A fan blows the warm air from the roof area through the hayloft. A full cost calculation as part of a bachelor's thesis at the Technical University of Munich showed the system with a double-skin roof to be very interesting economically.

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 salvaging technology for leafy hay, especially alfalfa hay. An important parameter for the evaluation are the losses occurring during the hay preparation, these are mainly composed of respiration and friability losses. If these losses are now assigned to the respective process step in hay preparation, the result is a value of 2.2 to 4.4% for mowing, 6 to 20% for tedding, turning and windrowing, and 4.4 to 11% for salvaging. Advertising therefore has a key role to play in minimizing crumble losses. Consequently, the first year of the trial focused on crumble losses during hay advertising. The first step was to optimize the methodology for recording crumble losses. Through the intensive further development of the methodology, a better reproducibility was achieved. The innovative "broom method" proved to be particularly suitable.

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

The sales manager for Germany, Heinrich Bührke, of the Finnish agricultural machinery manufacturer ELHO presented its special swath aerator and swathing technology: Both techniques have proven themselves in Finland in hay and straw collection for years, as they stand for low losses and high hygiene quality. Contamination is also minimized on land fertilized with farm manure, as the forage has little contact with the ground during turning and windrowing. Of particular interest here is drum raking technology, which was very common in Germany in the 1950s as push rakes. A major problem at that time were the dreaded drum winders whereby long hay wrapped itself around the turning drums. Today, this is no longer an issue due to the installation of scrapers and the use of improved tines. The easy changeability of the drum speed due to the hydraulic drive 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 group of medium rakes, a good partner to the round baler.

Peter Weinand Division Manager Forage Harvesting of the German agricultural machinery manufacturer CLAAS presented the current forage harvesting technology and impressed with technical innovations. He covered everything from mowing technology to loader wagon or baler technology and emphasized correct machine settings as the greatest potential for reducing forage losses. CLAAS still has considerable potential in the area of haymaking technology: improvements should be made in operational safety, impact force, protection of the forage and the sward, drying time, degree of soiling and forage losses. CLAAS has already introduced a number of innovations to achieve these goals, such as the "Active Float" mower's optimum contact pressure and the "Max Spread" tedder's higher pick-up capacity. Other sensors and systems for moisture measurement and automatic machine control will be coming onto the market in the next few years.

Jochen Burmester from the DLG Test Center Technology and Farm Inputs in Groß-Umstadt explained in detail the various test procedures and measurement technology used by the DLG. He presented both the crop production technology test portfolio and explicitly the procedures 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 then lead to the various DLG test marks, e.g. the DLG Focus Test, which is a support for the farmer when purchasing machinery.

Alfred Pöllinger from LFZ Raumberg-Gumpenstein focused on gentle hay drying. He explained the application limits of hay drying and presented various system solutions. In particular, he addressed constructional and technical implementation details. From his point of view, round bale drying has some important advantages, for example, this technology is well known in practice and can be successfully implemented in terms of labor economy. Storage space requirements are practically 20% less and the bales can be handled easily. However, round bale hay is also particularly susceptible to mold and airflow into the bales is determined at the time of baling. The capacity of these systems is usually less than that of drying systems for loose green forage. He described the operating limit of a round bale aeration system as a water content of 30%. He went on to discuss key figures of intake and crumble losses as well as their determination. As important prerequisites for a functioning round bale aeration system, he also mentioned 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. This can be done by the waste heat of a biogas plant or by wood heating to max. 50°C, by solar under-roof extraction. The use of a dehumidifier can accelerate the drying process.

Susanne Jakschitz-Wild from the State Institute for Agriculture in Freising showed in her presentation very clearly and well-founded many practical examples of drying for 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 will ultimately lead to setting recommendations.

At the end there was still the possibility for discussion and deepening of topics, of which also active use was made. Björn Bohne thanked the speakers and participants and asked the participants to leave contact data if they are interested in the project to possibly participate as a test farm in the next years.

Press release 04.12.2013 An underestimated feed: Expert talk in Frankenhausen on modern haymaking techniques