Home » Issue 27-2023 » Company insights » Perfect seed placement in different conditions (Philipp Horsch)

Perfect seed placement in different conditions

The HORSCH portfolio in the sector of disc coulters is varied and adapted to global challenges and increasing requirements for precision in agriculture. Philipp Horsch talks about the challenges, developments and precision.

terraHORSCH: The Agritechnica lies behind us. How did HORSCH present the disc seed coulters at the show?

Philipp Horsch: Our objective was to present a wide range of seeding technology to be able to show solutions for all requirements worldwide. We presented a total of five different disc coulter systems. This variety developed dynamically in the past ten years. One factor behind this development is our increasing globalisation and internationalisation. As a result, we were faced with more and more requirements with regard to the coulter technology which we wanted to meet. Another reason was to take the next step towards precision in our existing markets to be able to react to all conditions and always ensure a perfect seed placement. The climate change (wet/dry conditions), too, required additional adaptions in the existing markets.

How has the TurboDisc coulter developed in the past years?

Since the end of the 1990s, we used rubber bearings as coulter holders. They ensure a higher power in the coulter systems. Over time, farms became larger and wanted to seed more and faster. Accordingly, major importance was attached to the stability of the coulters.
Another issue were the scrapers between the discs. In this respect, we tried to change a few things over the years and then realised that the original scraper we developed right at the beginning was still the best in terms of operational safety and work quality.
One aspect that we worked on for years is the issue of the seed release in the coulter and the question of whether to place the seed in front of or behind the disc bearing. We realised that it is a great advantage to place the seed in front of the bearing as this significantly increases the precision of the depth placement. Our range also offers versions with a placement at the rear where we divert the seed flow and bring it to the front. This also works but requires more effort.

How did the importance of precision become apparent?

One of the assumptions which we have always based our developments on is to increase the efficiency and the precision of machines and work processes in the fields. It all started in 1990 with the globalisation of agriculture. The initial challenge was to ensure operational reliability under the new conditions and to seed properly. At that time, farms focussed on efficiency. This was why we didn't think so much about precision, but the requirement rather was to seed at the right time, combined with improvements in the tillage, crop care and fertilisation sector. This is how the topic of efficiency developed very well.
The next step automatically is to focus on precision. The reason is that yield increases develop towards stagnation, and the question in this respect is where there is still potential for optimisation. With a lot of topics like genetics, climate and maintenance, we obviously reach the limits. One remaining lever is precision. And the optimum with regard to precision is single grain seeding. We have been knowing this since the 1980s when the first tests were carried out. From a technical point of view, it has been difficult for many years to put this into practice. We were the first to be able to carry out real single grain seeding in cereals. And in this respect, we possibly still see an opportunity to take the next steps.

"The application range of our seed coulters is characterised by the clay content of the soil and the intensity of tillage before seeding. In most conditions, our standard TurboDisc coulter is used (light brown in the diagram). Both on free-flowing soils with mulch seeding or after more intensive tillage, it places the seed safely and efficiently in the soil. It reaches its limits on very heavy soils with a high clay content and for direct seeding. A few years ago, we decided to offer another coulter system with a higher penetration force for direct seeding. To meet the requirements for a precise placement of seed in uncultivated soils, we developed a single disc coulter with an individual depth control. Our Avatar line is equipped with the SingleDisc coulter. Customers also use it for mulch seeding in heavier soils. Especially farms that want to move little soil while seeding rely on the single disc coulter technology. In practice, both TurboDisc and SingleDisc coulters can be found in these sites. This overlap between the areas of application can be clearly seen in the diagram (SingleDisc light green).
For farms with highly variable soils, from sand to extremely heavy soils, we will offer the ParaDisc coulter in addition to the standard TurboDisc coulter in the future. Due to a slightly higher possible coulter pressure and the parallelogram connection, it remains safely in the soil even in extremely heavy soils. The possible range of application will overlap with the TurboDisc and Single Disc coulter (dark green in the diagram) in many areas. Our DuoDisc coulter which was specifically developed for the requirements of our mechanical power harrow combination Versa 3 KR, is shown in the diagram in dark brown."

Dark brown: DuoDisc coulter application range
Light brown: TurboDisc coulter application range
Dark green: ParaDisc coulter application range
Light green: SingleDisc coulter application range

How has precision in coulter technology developed at HORSCH over the years?

We have been optimising precision for many years. We are constantly making further developments, especially in the sectors of seed depth, spacing and seed environment. The double disc coulter, for example, was a quantum leap.
It automatically achieves greater precision as the design is completely symmetrical. A smoother running of the coulters is also very important in this respect. We achieved this by means of rubber bearings, high coulter pressure and a stable double disc coulter. To achieve precision, as a first step, the depth control by means of the following press wheel was important. The next step was the uniformer which ensures that the seed is fixed at the bottom of the seed furrow even at very high operational speeds.
In a next development step, the skid, the catching roller and single grain seeding were combined by the SingularSystem. This system is highly complex and has high requirements on the seed. This is why it unfortunately never penetrated the market and remains in a niche for high-yield regions. Therefore, we focus on using the findings from the Singular coulter development for developments that we can use on a wider scale.

What are the relevant aspects when it comes to precision?

With our AutoForce system, we have automatic control systems for depth placement and reconsolidation ready for series production, and we can now also offer the combination with site-specific seeding. The coulter technology becomes more and more complex the more elements we introduce (skid, catching roller etc.), but we still have to make sure that the operational safety is always guaranteed. With the further development of the double disc coulter towards the ParaDisc+, we can very easily change the elements of this coulter that penetrate the soil. This means that we can very easily remove for example the skid and the catching roller and replace them with a normal drop tube for very difficult, wet conditions.

The new Solus is a parallel development for which we used the experiences gathered from the Maestro family. On this basis, we developed a concept for row spacings from 22.5 cm with which we can also seed cereals or rapeseed. At the moment, it is still too early to say if this makes sense. The machine is very complex, and we first have to find out where the opportunities and limits of this Solus system lie. What we can already say today is that the additional consolidation at the left and at the right side of the disc that we know from maize and soya seeding is very positive as it creates an even, consolidated seed horizon around the seed. These positive advantages already become apparent in cereal seeding as the result is a much evener emergence. Now we have to find the significant advantages of the system. We see obvious advantages, like a very precise placement, but also challenges, and we keep at it. And we will also test if the Solus can also be used for other crops. Then we'll know if it works and if it makes sense. We will gather these experiences and automatically transfer them to other coulter systems and other machine types.

Why does HORSCH also offer single disc coulters in addition to the wide double disc?

The single disc coulter is particularly ideal for markets which deal with direct seeding or at least rotative direct seeding. The focus is not exclusively on direct seeding, but there are situations in which a farmer seeds a crop directly in his rotation. The climate change is one of the reasons why people in Germany currently think more about this topic. The main point in this respect is how to keep water in the soil, and direct seeding is an appropriate method to do so. Due to its shape, the single disc coulter automatically has the dynamics of always pulling to one side. The requirements on stability, thus, are enormous. It was important for us to find a solution that would last, and we succeeded. This is why the single disc coulters in our portfolio are essential as we want to cover all conditions and provide farmers with the appropriate technology. Therefore, our portfolio also includes tine seeding technology which we offer in a wide range of machines from 3 to 24 m working width. They have also been developed for special requirements and are mainly used in the classical direct seeding regions. The clearing effect of the tine coulters ensures a residue-free seed furrow, especially on stony soils and in case of a high amount of harvest residues.

A look into the future

Looking far into the future, everything we do will be centred around the individual plant in the long term. This means: from seeding and nutrient supply to maintenance. Our focus will be on the individual plant.