Innovativ teknologi for ugrasbekjempelse

The project includes two new types of implements with the aim to control perennial weeds. The goal is to reduce the need of chemical pesticides, as well as reducing nutrient leaching and soil erosion. The first implement cuts the weed roots vertically (weed species with shallow root systems), the second cuts the weed roots horizontally (weed species with deep root systems) both leaving the soil surface more or less intact. The vertical cutter has been used for controlling of cough grass in meadows with clover and grass. These experiments has been located in Sweden and shows a reduction of rhizomes and the amount of ryegrass increased (newly established meadow). Similar test plots were established in different soil types (light soil/heavy clay soil) in old meadow with substantial amounts of couch grass. The results is not yet statistically evaluated. In a three-year autumn tillage experiment in a field with steep slope the root cutter has been compared to disc harrow and no stubble treatment. There were no difference in loss of soil and phosphorus between the test plots for the root cutter compared to no treatment and it was significantly less compared to disc harrow. This result is very interesting and we can expect to get the allowance to use the root cutter even in autumn in areas exposed for erosion. Root cutting in spring at 20-25 cm depth has reduced the amount of cirsium arvense substantially in combination with no ploughing or shallow spring ploughing. When spring ploughing to 25cm, the root cutting has no effect. On other types of perennial weeds the root cutting has not given any clear results, but deep ploughing has. The yield is highest when ploughing to 25 cm depth. When no ploughing, the root cutting effect increases with cutting depth. In a multi-year experiment comparing ploughing/non ploughing, there were less perennial weeds and higher yields on the test plots including ploughing. The last two years half of the test plots was including root cutting in autumn at 10-15 cm and half of the test plots with no ploughing was root cut in spring. It was most weeds were no cutting was done and were it was cut in autumn and ploughed in spring. The same is valid for cough grass. Root cutting in autumn reduced the amount of sonchus arvensis. The yields was highest after ploughing and lowest after no root cutting or no ploughing. The vertical and the horizontal cutter was included in a three year autumn tillage experiment in Norway and compared with other intensive tillage methods: rotary tiller, disc harrow, tine based stubble cultivator and combinations of these. There were no significant difference in the amount of perennial weeds for disc harrow, stubble cultivator and root cutter. A similar two-year experiment was made in Sweden, but only including the root cutter, disc harrow and stubble cultivator. For couch grass there were different results in Norway and Sweden. In Norway there were slightly less couch grass were the root cutter was used compared to disc harrow and stubble cultivator. In Sweden this was opposite. A reason might be that the tillage was done twice during the autumn in Sweden as in Norway only once due to too wet soil conditions. In Sweden it was less cirsium arvense were the root cutter was used compared to the disc harrow and the stubble cultivator and substantially less compared to no treatment. The vertical cutter in combination with the horizontal cutter or stubble cultivator gave a reduction of perennial weeds, but the root cutter as a single operation gave weaker results. It was a problem to get the vertical cutter go deep enough. In an experiment with root cutting to 25cm depth and ploughing to 25 cm or 15 cm gave a varying result for different types of weeds. In test plots with deep ploughing the root cutting had minimal effect. Shallow ploughing resulted in more cirsium arvense compared to deep ploughing. In a one year experiment with no treatment after root cutting the results showed that the germination of cirsium arvense was at a minimum when cutting in medio May. The root cutter has been used by farmers in both Norway and Sweden and they have revealed design deficits that has to be improved before the machine can be ready for the market. The experiments has shown that the root cutter is interesting in both organic and conventional farming for fighting perennial weeds. Using the root cutter in autumn leaves a surface with low risk of erosion and the effect on reducing the perennial weeds are in most cases at the same level as more intensive tillage. The root cutter is interesting for areas exposed for erosion due to the topography. This gives a good fundament for further improving the machine and finally commercialize it. The problem experienced with the vertical cutter to penetrate the soil and to go deep enough even with additional load added has lead us to stop further development of it.

Prosjektdeltagerne har tilegnet seg ny kunnskap omkring mekanisk bekjempelse av utvalgte rotugras. Samspillet mellom jord, plante, teknikk og tidspunkt er i denne sammenheng essensielt. Videre er det gjennom dette arbeidet kommet fram til et funksjonsdyktig redskap som det er faglig grunnlag for å kommersialisere. For Kverneland vil resultatene av prosjektet gi et godt grunnlag for å kunne ta stilling til evt. når og hvordan kommersialisering av produktet kan være aktuelt. Effekten av prosjektet for framtidige kunder vil være at det medfører en mulighet til å kunne holde utvalgte rotugras i sjakk samtidig som man i stor grad tilfredsstiller de politiske føringer som er gjeldende per i dag knyttet til for eksempel krav om integrert ugrasbekjempelse, begrensning av erosjon mm. Resultatene av prosjektet har vakt interesse også internasjonalt og flere forskningsmiljøer har tatt kontakt for å se på muligheten for å jobbe videre med grunnlaget som er lagt i dette prosjektet.

Trenden i jordbruket i Europa er at et økende areal blir dyrket uten pløying. Dette er ønsket fra myndighetene fordi redusert jordarbeiding reduserer uønsket avrenning av næringsstoffer til vassdrag og hav (erosjon). Redusert jordarbeiding gir reduserte kostnader, og det kan være en drivkraft. Imidlertid fører redusert jordarbeiding til større forekomst av rotugras, og dette har ført til økt bruk av kjemiske plantevernmidler mot ugras, noe myndighetene ikke ønsker. Andre redskaper som kan redusere bruken av kjemiske midler finnes, men disse gir kraftig bearbeiding av jorda som igjen kan øke erosjonen. Ideen, innovasjonen det søkes om ligger i det å konstruere redskaper som kan bekjempe rotugras uten pløying, men som ikke gir kraftig bearbeiding av jorda. Kverneland har ideen til to nye redskaper som kan oppfylle disse kravene, men før de kan lanseres på markedet må det kunne dokumenteres vitenskapelig at de virkelig oppfyller målet. Redskapene kan få et stort potensiale innen økologisk dyrking. Innovasjonen ligger i skjæringspunktet redskaper, jord og biologi. Kverneland innehar kompetanse når det gjelder å konstruere redskaper og vi kan mye om jord, men mangler kompetanse på biologi. Vi har heller ikke kompetanse når det gjelder vitenskapelige feltforsøk, som må til for å kunne dokumentere effekten. NIBIO, NMBU og SLU har kompetanse på de områdene vi mangler, og vi ønsker at de gjennomfører disse forsøkene. Vi har allerede utnyttet deres kompetanse i utformingen av ideen. Forsøkene skal avdekke hvordan og når på året redskapene skal brukes. Det søkes om et forsøk over 3,5 år for i størst mulig grad fange opp årsvariasjoner. Vi ser på lansering av redskaper som representerer et helt nytt konsept uten dokumentasjon på virkning som dødfødt. Imidlertid er det en økonomisk risiko dersom vi må legge ned store midler i et prosjekt, hvis resultat vi ikke vet svaret på. Det er en teoretisk risiko at plogsalget går ned dersom omlegging til redusert jordarbeiding fortsetter