David Hansson

My research is focused at the interface between biology and technology, with an emphasis on sustainable approaches to weed management, primarily in organic farming but also in integrated production systems. This involves developing knowledge and methods that enhance crops’ competitive ability against weeds while reducing the need for chemical inputs.

A central area of my research concerns the potential of cover crops, where I investigate their weed-suppressive properties as well as their effects on nitrogen dynamics (N-min) in the soil profile. I have also studied spring barley and spring wheat to identify varietal traits that improve competitiveness against weeds. In organic spring barley production, I have examined how row spacing and seeding rates influence both yield and weed occurrence. I have further explored the role of crop rotations in achieving long-term weed control.

Another part of my research focuses on row-grown vegetables and fruit production, where I evaluate mechanical and thermal weed control methods. I have also worked on integrated strategies in onions and autumn-sown crops, as well as on challenges arises by problem weeds such as blackgrass in cereals. 

Besides studies on arable land, I have investigated alternative weed control methods for hard surfaces, studying mechanical and thermal techniques as well as the use of acetic acid as an alternative to conventional herbicide-based control.

Through these studies, my research contributes to the development of more robust, sustainable, and integrated weed management systems, in which the crop’s own competitive ability is combined with mechanical and thermal methods to create effective weed control strategies.

Ongoing research projects

• Participant-driven project concerning systems that benefit the soil health, carbon sequestration and soil fertility. Funder: Swedish Board of Agriculture. (Project Leader David Hansson).
•  How much nitrogen is left in early spring in a leaching-prone soil after intermediate crops? Funder SLU Partnership Alnarp. (Project Leader David Hansson).
• Growing system with intermediate crops and smart management of tops for effective climate benefit. Funder Swedish Board of Agriculture. (Project Leader Åsa Olsson).
• Intermediate crops in the crop rotation for increased soil fertility and reduced climate impact. Funder SLF. (Project Leader Åsa Olsson).

Completed research projects 

• Control strategies against nightshade and hairy nightshade, including short fallow and inter-crops, in an organic crop rotation with potatoes, carrots and onions.
• Improved weed control effect in carrots through prolonged germination period, combined with false seedbeds and delayed sowing.
• Integrated weed management in onions.
• Project Leader for three projects on “Weed control in organic grown vegetables” during 2006–2014. The projects were designed according to the research methodology of “participatory research.” The research was conducted on farms.
• Control of black-grass (Alopecurus myosuroides Huds.) through various integrated cultivation measures.

I educate students in weed control in organic and integrated cropping systems for agriculture and horticultural production, as well as in methods for weed control on hard surface areas. I also teach weed biology and the identification of weed species.

1991 - Master of Science in Horticulture at the Swedish University of Agricultural Sciences (SLU), Alnarp, Sweden.

2002 - PhD in Agriculture (AgrD) at the Swedish University of Agricultural Sciences, Alnarp, Sweden.