Findings of a bachelor thesis - Supervised by HORSCH and the HOCHSCHULE WEIHENSTEPHAN-TRIESDORF | Faculty of Agriculture After the harvest, they can be seen everywhere: stubble fields. Organic matter remains on them, especially straw that does not only serve as a useful by-product, e.g. as raw fibre in animal food or as litter, but also plays an important role directly in the field. In this respect, the correct incorporation is important. If the organic matter is distributed evenly in the cultivation horizons, it encourages important processes like: Humus build-up for long-term soil fertility Rooting for an optimum soil structure Strengthening the water balance Erosion protection Nutrient release An uneven straw distribution may result in a limited nutrient availability, rot in compacted or wet soil layers as well as uneven growth of the following crop. Moreover, the risk of diseases increases, and the seeding technology can be impaired – e.g. because of clogging or uneven seed placement. The question is: how can the quality of straw incorporation be visibly and objectively assessed, and are there differences between disc and tine machines? A field test as a practical example To examine this precisely, the straw incorporation of two common tillage machines for stubble cultivation was compared in a field test that was set up within the scope of a bachelor thesis: Shallow cultivator Cruiser Due to the long, multi-bar design (4- to 6-bar) and the narrow tine spacing of the tines, the cultivator captures the straw on the whole working width and distributes it across the field. Compact disc harrow Joker As the discs are arranged in pairs, the compact disc harrow can incorporate large quantities of organic matter. In the test, the Cruiser 7 XL with 8 cm wide tine points and the Joker 6 RT with serrated discs (52 cm diameter) were used. To ensure the comparability of the work results, the knife roller of the compact disc harrow was lifted. The field test was carried out on a threshed rye field. Because of the long straw, it was mulched at a height of approx. 5 cm in advance, and the organic matter was crushed to a length of about 10 cm. The test strips were then cultivated twice with both machines – once shallow with a working width of 7 cm and once deep with 15 cm. All passes were carried out at a speed of 12 km/h.Assessing straw incorporation: traditional vs. KI-based Traditionally, the straw distribution is assessed according to the so-called Voßhenrich Method: a profile wall is uncovered, a grid is placed over it, and each cell is estimated according to six steps (0 to 100 % coverage). Although his method is established, it strongly depends on the experience of the person carrying out the evaluation – and is very labour-intensive. The AI-based evaluation is the modern alternative: a camera films the soil profile while ploughing, and a trained neuronal network recognises the straw on the images in a pixel-perfect way. Thus, AI provides quick and objective results directly in the field. What does the field test show? Results at a glance The comparison between visual rating and AI-based evaluation only shows minor differences: both methods provide almost identical courses and clearly visualise the different working methods of the tillage machines. Joker: Cuts the soil and mixes the straw mainly in the middle soil layer (5-10 cm) where a coverage of about 40 % is measured. In the upper 0-5 cm and the lower 10-15 cm layers, the share amounts to just over 20 % respectively. Cruiser: Leaves the majority of straw in the upper working horizon of 0-5 cm (over 50 % coverage). Between 5 and 10 cm, the degree of coverage amounts to approx. 30 % and to 20 % in the lower layer.Summary of the test – what remains? In stubble cultivation, the cultivator as well as the compact disc harrow have an influence on the straw distribution in the depth. The different working methods of the two machines leave specific “fingerprints” in the soil profile: While the Cruiser (tine machine) incorporates the straw mainly in the upper 5 cm, the Joker (disc harrow) ensures an intensive mixing of organic matter especially in the medium layer between 5 and 10 cm. Conclusions for practical use: disc harrows are ideal if the straw is to be mixed in intensively in depth, while tine machines are particularly suitable if the objective is an even distribution of the harvest residues on the surface. More details about the two machines: Cruiser 7 XL Joker 6 RT Design 6-bar 17 cm tine spacing FlexGrip tines with a release force of 180 kg 52 discs DiscSystem with 17 ° cutting angle Tools Points Tine point 5 cm Tine point 8 cm Tine point 10 cm Wing point 20 cm FlexCut point 24 cm Disc Serrated Ø 52 cm Serrated Ø 58 cm CoverCrush disc Ø 52 cm Working depth Max. 15 cm Max. 15 cm Mixing effect Even distribution in the upper 5 cm Intensive mixing in depth Basic applications Shallow to medium-deep tillage for stubble cultivation and seedbed preparation. For a shallow and quick incorporation (straw, organic fertiliser, catch crops) Additional tools Various packer options MiniDrill Crossbar: for levelling Knife roller: for additional crushing Seed bar for sowing catch crops MiniDrill Special features Contour following Flexible tine segments that can move downwards by -2° and without any limit in the positive direction ensure an optimum following of the soil contour and an all-over cutting SoftRide system Suspension system with integrated nitrogen accumulator reduces vibrations that are caused by the lifted transport wheels in the field and prevents the machine from rocking Learn more about Cruiser and Joker: Joker RT Working width 5,15 - 12,25 m DiscSystem discs Ø 52 - 58 cm DiscSystem disc thickness 6 mm Cutting angle DiscSystem discs 17 ° Cruiser 7 - 9 XL Working width 7,50 - 9,00 m Transport width 3,00 m Tine spacing 17,00 cm Maximum working depth 15,00 cm
