Tillage field trial more than doubled the emergence of volunteer seeds and black-grass

Carrier XL 725 with CrossCutter Disc Aggressive

This summer, Väderstad conducted a field trial of ultra-shallow tillage in harvested wheat stubble. The trial compared passes with a Väderstad Carrier XL disc cultivator equipped with conventional 610 TrueCut discs and the same machine fitted with CrossCutter Discs. It found that volunteer cereal seed emergence increased by 105% and the emergence of the difficult-to-control grass weed black-grass increased by as much as 174%.

– Black-grass is a major problem throughout Europe, largely because it can be resistant to chemical control and because its seeds risks entering a state of dormancy. This means that, once the plant has shed its seeds, it can remain a problem for generations of farmers, says Nina Pettersson, Chief Agronomist at Väderstad, adding:

– One effective way to control this weed is to ensure that the seeds germinate as soon as possible after harvest, so that the weed can subsequently be controlled—often within a couple of weeks—by mechanical or chemical means.

The trial was conducted in Frömmstedt, Thuringia, south-east Germany, on 28 July 2026, using replicated field plots in which the same machine was operated with either two rows of 610 TrueCut discs or CrossCutter Disc for ultra-shallow cultivation on two or three axles. In the first treatment, the machine was used with the most common equipment, settings and speed: 610mm TrueCut discs set to a shallow working depth of approximately 5cm, providing full-width cutting. The speed was set at 15km/h. Different speeds and numbers of disc rows were then tested, along with CrossCutter Discs, which provide full-width cutting at an ultra-shallow depth of 3cm. This produced remarkable results for the emergence of weeds and volunteer cereals.

By changing the TrueCut discs to CrossCutter Discs the results was improved. Adding a third disc axle improved the results further. The best results were achieved by using CrossCutter Discs on three axles and increasing the speed to 20 km/h.

– This will be the new standard, says Wolfram Hastolz, Commercial Manager Tillage, at Väderstad.

We found that operating a standard Carrier XL with two rows of TrueCut discs at 15 km/h resulted in the emergence of 88 volunteer cereal plants/m² and 96 black-grass plants/m². When we instead used a Carrier XL with three rows of CrossCutter Discs at 20 km/h, the number of volunteer cereal plants increased to 179/m² and the number of black-grass plants rose to as many as 263/m².

– This means that we can now change the standard approach to controlling black-grass: instead of two rows of discs at 15 km/h, we should use three rows of discs at 20 km/h, says Wolfram.

All machines used in the field trial are part of Väderstad’s product range.