The limitation of readily plant available nutrients is a common feature of many alternative fertilisation systems avoiding the use of mineral fertilisers and nutrients are frequently sequestered in complex organic or sparingly soluble inorganic compounds. Other common stress factors with increasing significance for European agriculture comprise drought and high temperatures linked with global climate change particularly in Mediterranean areas but also in Central Europe. Also low soil temperatures during early spring in Central and Northern Europe cause limitations particularly for crops of tropical origin such as maize, soybean or tomato. Apart from water limitation or temperature extremes per se, all stress factors are additionally associated with limitations in plant nutrient acquisition.
Therefore, the general goal of WP04 is to assess functions and benefits of bio-effectors in stress environments in order to provide specific guidelines for their effective use in resource-limited agriculture. The specific objectives of WP04 are: characterisation of bio-effectors able to improve nutrient acquisition under conditions of limited nutrient availability, low root zone temperatures, drought stress and high salt concentrations. Although, salinity is not a major stress factor in European agriculture, high salt concentrations may cause problems for the effectiveness of bio-effector application in association with local fertiliser placement strategies. Output of WP04 will further support the activities in WP05 (Organic Farming), WP06 (Recycling Fertilisers) and WP07 (Fertiliser Placement).