An important characteristic of organic and “low input” production systems is the more frequent use of manure and other organic matter based fertilizer inputs (e.g. green manures, composts). This type of inputs and the prohibition (in organic systems) or reduced use (in other “low input” systems) of soil pesticides is thought to result in environmental, biodiversity and/or agronomic benefits (e.g. increases in soil biological activity, earthworm biomass, soil aggregate stability, organic matter content, erosion resistance). In addition, some organic matter based inputs are known to reduce the disease incidence in crop production systems.
Nitrogen release characteristics from organic matter based fertilizer inputs.
The nutrient availability pattern in soils (in particular of N and P) receiving organic matter based fertilizer inputs (OMFIs) is more difficult to predict than the nutrient availability from mineral fertilizer inputs. This is mainly because a large proportion of nitrogen and phosphorus present in OMFIs is in organic form and only becomes available after mineralization by the soil biota. The mineralization potential in soil is known to be influenced by environmental conditions, “inherent” soil biological activity and plants growing in soil. It has also been shown that the “inherent soil biological activity” can be increased by specific long-term soil management practices.
Soil-mediated disease suppressiveness
Although the phenomenon is well described in the literature, there is still insufficient information about the mechanisms and modes of action resulting in (a) inherent soil suppressiveness (resulting from specific long term soil management practices) and (b) short term suppressive effects resulting from specific organic matter based fertilizer inputs (Berner et al, 2002; Bullock & Ristiaino 2002). The lack of understanding of the underlying mechanisms and “modes of action” makes it difficult to increase the efficacy and commercial use of crop protection strategies based on long-term soil management with suppressive organic matter inputs..
The work-package led by FiBL in this project focused on:
European Union, 6th Research Framework Programme
Work package leader