Volume 72 (2021): Issue 3 (September 2021)

According to experts, pasturing in Europe has been decreasing for many years. Today, a lot of different pieces of regulation in Germany and in Europe exist, affecting farmers when they bring their cows to pasture. Furthermore, there are social requirements for pasturing, which need to be considered. Factors like increasing relevance of animal welfare, environmental protection, and the recreational use of the environment and esthetics of landscape come into play. Therefore, scientific research and new solutions are needed. This paper aims to give an overview across selected pasture-related regulations affecting farmers in Germany and Europe. Furthermore, aspects which are not directly regulated by the government, but are expectations of society will be highlighted. Concluding from this, technological possibilities - already on market and in the pipeline of scientific research will be described. Results show that today several different attempts are made to improve pasturing. Most of these attempts focus on improvement of management tasks. Attempts also directly focus on technological improvements. It can be concluded that new tools for pasturing can increase productivity and simultaneously decrease management tasks. Nevertheless, pricing of these tools as well es the amount of bureaucracy will be the most crucial factors for their adaptation.

Electrification is done in newer tractors hesitantly. There will be an increase in the need for electrified mounted implements and application units. Semi-liquid manure and degestate from biogas crops are increasingly injected directly into the soil. This technique reduces nutrient losses and ammonia emissions. In the case of loamy soils and clay, a high draft force is needed for slurry deposition into the soil. With the development and testing of an application unit with reduced working width of 3 m, the draft force reduction was found to be lower by nearly one third. The field trials have been performed in two steps: first, a prototype with spiked roller and star packer as a traction element on the roller unit in 3-m working width and second, a final slurry grubber with 6-m working width and cutting coulter on the traction roller. We tested both devices with and without powering the electrified traction roller. These field tests took place on six fields near Freising in Germany. Results showed that firstly, draft force reduction up to 35% was achieved with a powered traction roller on the mounted implement having 20% slippage on the traction roller. These values were obtained by pulling a tractor with the electrified implement by another tractor in a horizontal ground level. Second, we observed a different variation range of the values among the three test fields. This results from differences in the soil structure on the test fields having pebbles and stones near the soil surface or bigger stones down the working depth of 22.5 cm. The presented results show new kinds of working scenarios and operation modes for agriculture. Electrification can be an advantage in taking care of nutrient losses and ammonia emissions as it leads to a draft force reduction on heavy soils.

The handling of multi-outputs in life cycle assessment (LCA) is a controversial topic in both LCA application practice and the literature. Although there is a prescribed hierarchy of how to deal with multi-outputs, which favors system expansion (including co-products and their upstream chains) as the most scientific solution over the allocation approach (dividing environmental impacts based on an allocation factor), the latter is still most common. In this study, system expansion, mass, economic, and energy-based allocation are studied within a biosystem engineering case study, which provides two marketable outputs, biogas and nano-cellulose. The global warming potential (GWP) is used as basis for comparison. There is hardly any difference between system expansion and economic allocation, but it is also shown how problematic the latter approach is for newly introduced products because the market price is still very high and not representative. Results show that the GWP with mass allocation has the lowest impact; however, this approach is inappropriate since the outputs are a solid product and biogas, which are hard to compare based on a mass basis. Overall, based on the studied approach, results can be significantly different. Hence, it is recommended to avoid comparison and interpretation of results when using different modeling approaches.

Optical crop sensors for variable rate nitrogen application (VRNA) are described as an optimal solution to increase yield while minimizing fertilizer costs, although their operation and acquisition costs could be high. In this study, a partial budgeting approach was used to assess the net income of buying and operating a crop sensor for VRNA for optimizing fertilizer application to winter wheat. Two VRNA scenarios – stimulus, where crops with lower yield expectations received more fertilizer, and compensatory, where crops with higher yield expectations received less fertilizer – were assessed and compared to a conventional way of fertilizer application. Both scenarios showed negative results. The stimulus scenario showed a yearly negative change in income of −227.3 €/ha/year on 25 ha of fertilized area and −38.9 €/ha/year on 250 ha of fertilized area. In the case of the compensatory scenario, a yearly change in income of −271.8 €/ha/year on 25 ha of fertilized area and −83.3 €/ha/year on 250 ha of fertilized area was achieved. Results also showed that bigger farms had lower losses than smaller farms due to the economy of scale. Farmers may opt for sharing or leasing the use of the crop sensor to reduce costs.

Precise localization and reliable navigation are of crucial importance in order to fully automatize tasks in agriculture using field robots in an outdoor environment. However, under certain conditions, absolute localization accuracy of outdoor positioning systems, mainly global navigation satellite systems (GNSS), might drop under a critical threshold. Thus, field robots must rely on indoor positioning methods such as laser scanners and adaptive Monte Carlo localization (AMCL) in order to maintain necessary localization accuracy. Here, the localization accuracy of the field robot “Mathilda” using such an indoor positioning method is evaluated in a realistic scenario, in this case, an outdoor laboratory with plant pots aligned in rows. For this, the positioning error of the robot was determined using a motion capture system. The results showed a mean absolute distance error over all positions of 198.9 mm and a mean angular error over all positions of 4.9°. Most likely, limitations by the differential drive system, the large pneumatic tires, and unsatisfactory path planning are responsible for this large deviation.