Lignin in the root zone of plants, mechanisms of action
Dep. of Plant and Environmental Sciences
Project leader: Åsgeir R. Almås
Co-workers: Lars R. Bakken, Tore Krogstad
Source of funding: Borregaard
Project period: 2006-2007
Several field trials (in Australia, USA and South Africa) where BorreGRO (lignin) was added to the soil in combination with (or soon after) sowing have demonstrated substantial positive (but somewhat variable) effects on final yields of wheat, potatoes and melon. In various greenhouse experiments, it has been demonstrated that BorreGRO has a stimulating effect on early root development. The effect appears to be strongly concentration dependent, the optimal doses are normally very small and higher doses appear to have a negative effect under some circumstances. The effects appear to be strongest when conditions for plant growth are suboptimal. The circumstantial evidences acquired through various experiments suggest that more than one of these mechanisms may be real, and that they may have great economic and environmental value in both horticulture and agriculture.
The proposed project seeks to explore the lignin’s mode of action based on various hypothesis modes:
- lignin may improve plant performance in an early critical stage after germination by transiently lowering toxic concentration of aluminium in soil solution.
- lignin is a significant ion exchanger in the soil, which interfere with (enhance) phosphate availability and reduce salt stress on plants and microorganisms
- lignin carries essential macro- and micro nutrients, and lignin addition may hence fuel early plant growth.
- lignin affects the microbial growth and community composition (bacterial and/or fungal), hence indirectly affecting plant roots
