Development of strategies to optimise soil quality characteristics (mineralisation capacity and diseases suppressiveness)
Recent studies have shown that the biological activity and microbial biomass in soils increases after long term “organic” management especially in soils receiving regular inputs of organic-matter based fertility inputs. Recent studies with potato also indicate that in “long term” organically managed soils, nitrogen inputs via compost (with a high proportion of nitrogen and phosphate bound in insoluble form) resulted in significantly increased nitrogen use efficiency and yields and quality of potato crops compared to fertility inputs with higher proportions of water soluble N.
It has also been shown that specific soil fertility management practices can increase the inherent suppressiveness of soils against soil borne diseases and nematodes.
However, there is insufficient knowledge on the relationships between organic and “low input” soil fertility management (and resultant soil properties) and (a) the capacity of soils to mineralise nitrogen from organic matter based inputs and (b) the mechanisms of suppressiveness of soils against soil borne diseases.
There is also limited information on the effect of organic matter inputs on the physiological resistance of crop plants to foliar diseases. However, such knowledge is essential to develop improved soil fertility management systems for organic and “low input” crop production systems, since it may allow simultaneous reductions in: (a) nutrient losses through leaching, and (b) costs of plant protection and/or crop losses due to diseases, while (c) maintaining or improving product quality and yield. To address theses deficiencies in knowledge we will carry out the following studies (sub-workpackages):
WP3.1.1 Effect of long term organic, “low input” and conventional management and different fertility management practices on soil biological, physical and chemical characteristics. The work include soil analysis based studies using samples from a long term replicated field trial (DOC trial) in Switzerland and soils from different regions of the EU used in field experiments under WP3.3
WP3.1.2 Effect of soil biological activity on nitrogen mineralisation capacity, N-release pattern in soils and potential N-use efficiency. This include soil analysis and pot trial (vegetable crops) based studies using samples from a long term replicated field trial (DOC trial) in Switzerland and soils from different regions of the EU used in field experiments under WP3.3
WP3.1.3 Effect of soil biological activity and organic matter on soil suppressiveness and physiological resistance of crops. The work include bio-assay and soil/fertility input analysis based studies.