# The Development of a Forage Harvester Ensuring Two-Level Moving of Tall Stalk Forage
## 1 Introduction and Analysis of the Scientific and Technical Literature  
In modern agriculture, the preparation of high-quality stalk forage is a priority task for increasing livestock production efficiency. On farms, the harvesting of stalk forage (shredded hay, haylarge, and corn silage) is carried out by forage harvesters. There is a growing global interest in improving forage harvesting machinery, particularly for use in small- and medium-sized farming operations. On such farms, compactmachines that can operate efficiently under limited resources, complex terrain, and high crop density are of particular value. Research conducted at German universities, notably at the University of Hohenheim, focuses on the implementation of intelligent guiding systems integrated into harvesting units. Technologies such as machine vision and adaptive control enable the precise capture of forage material even on uneven fields with variable crop heights [1]. These systems contribute to reducing losses and improving forage quality. American companies, such as John Deere and New Holland, have introduced GPS-based navigation and automated plant guidance systems to optimize harvester movement trajectories. These technologies, also applied in trailed models, demonstrate high accuracy in delivering biomass to the chopping mechanism [2]. In China and India, significant efforts are being made to develop cost-effective compact forage harvesters. For example, Chinese engineers have proposed a small harvester with an adjustable guiding device that sets the intake angle and delivers stalks in an optimal position to the chopping drum. Field experiments showed a 12-15% reduction in corn harvesting losses [3]. In addition, Japanese researchers focus on precise chopping mechanisms to enhance forage digestibility. Rotor systems with a dynamic adjustment of cutting length are being developed to adapt to crop density and moisture content [4]. Despite these achievements, most of these systems are designed for large-scale farming and require substantial financial investment. For small farms, it remains essential to adapt such technologies while maintaining reliability and minimizing costs. Against this background, research into the development of guiding devices for trailed or compact forage harvesters is especially relevant. These devices aim to solve the problem of capturing tall stalks, particularly corn over 2 m in height, which is a known source of losses in existing machines. Thus, international experience confirms the feasibility of developing compact and functional guiding systems tailored to the conditions of small farms. This concept underpins the technical solution proposed in the present study. Modern self-propelled forage harvesters are highly productive and ensure the harvesting of stalk forage regardless of height and yield. However, they are designed for use on large farms, while their trailed versions are used on small farms. Among trailed forage harvesters, the Sterh and KSD-2.0 models are highly versatile. They are equipped with a moving rotor with L-shaped knives. The rotor with L-shaped knives permits the moving of stalk forage and picking up hay from a window, i.e., these machines ensure the harvesting of shredded hay, haylarge, and corn silage on small farms. However, the main disadvantage of these machines is that they do not permit the moving of tall corn stalks more than 1.5 m.  
In certain climatic regions, the height of corn stalks can reach 2.5 m.  
When tall stalks are moved, they are cut by L-shaped knives, rotate upwards relative to the front bar, and due to centrifugal forces are directed into the moving rotor chamber, where they are cut again by the knives at the level of the front bar. However, when the stalk height exceeds 2 m, after the second cut, the outer part of the stalk has a length of about 1.5 m and considerable mass. In this case, a significant part of the stalks falls to the ground and is not picked up, leading to considerable losses during harvesting.