“Bio-effectors are viable microorganisms and active natural compounds (e.g. microbial residues, composting/fermentation products, plant/algae extracts) whose direct or indirect effect on plant performance is based on the functional implementation or activation of biological mechanisms, particularly those interfering with soil-plant-microbe interactions. In contrast to conventional fertilizers and pesticides, the effectiveness of bio-effectors is not based on the substantial direct input of mineral plant nutrients, either in inorganic nor organic forms, or of a priori toxic compounds. Bio-preparations (bio-agents) as ready formulated products, applied with the purpose of stimulated plant growth (bio-stimulants), improved plant nutrient acquisition (bio-fertilizers), to protect plants from pathogens and pests (bio-pesticides/bio-control agents) or generally to advance cropping efficiency, can contain one or more bio-effectors along with other substances.” (Weinmann, 2010; Ph.D. thesis, Universität Hohenheim)
Well established bio-effectors with documented positive results on the field level are Rhizobia strains for soil/seed inoculation as a prerequisite for symbiotic N2-fixation when establishing new legume species/varieties. In addition, positive effects of mycorrhiza inoculation are reported for soils with (temporarily) low potential for natural root mycorrhization. Sufficient mycorrhization enhances nutrient (P) and water uptake and increases resistance against pathogenic fungi.
Further mechanisms for the positive impact of bio-effectors on plant growth were postulated, promising a high potential for resource preservation due to reduction of fertiliser and pesticide input: Active nutrient mobilisation by exudation of acids and carboxylates (e.g. P-mobilisation), exudation of micro-nutrient mobilising siderophores/chelates (e.g. Fe3+), reduction of trace elements from less soluble oxidised to highly soluble reduced forms (e.g. Fe3+ to Fe2+, Mn4+ to Mn2+), associative/non-symbiotic N2-fixation, protective antagonisms with plant pathogens, enhancement of mycorrhizal infection and growth, and stimulating hormonal effects.
Although many of these mechanisms are proven in principle, the reproducibility is mostly very limited, particularly when moving from controlled conditions in lab and pot experiments to real agricultural field conditions. The reasons for this failure remain speculative and range from simple problems with constant product quality to biological and ecological reasons related to complex and poorly understood antagonisms in the soil-root system. There are indications that there may be an inverse relationship between establishment of microbial strains applied to a soil and the intrinsic biological diversity of that soil. Consequently, the market for these products is still very limited and techniques for the on farm production/propagation of bio-effectors are not well established. Nevertheless, a wide range of bio-effector products for crop growth stimulation can be found on the marked worldwide.
The overall objective of this study is the preservation of natural resources by utilisation of the bio-effectors’ potential to reduce fertiliser and pesticide input. In more detail, the aim of this study is (1) to develop a common procedure for standardised testing of Bio-effectors both under green house- and field conditions (2) to understand basic principles, and to screen and optimise available bio-effectors under controlled conditions, (3) to test the most promising products under field conditions, (4) to understand underlying processes in the field necessary to (5) subsequently improve field applicability, and eventually (6) to promote the marketing of the final products which will be attractive for high and low input crop production within Europe and at the international level. A specific strength of this project is the successive development from the natural scientific process level (lab- and green house) to real field conditions and finally to the readiness for marketing.
To achieve these aims, different methodological approaches will be employed. Beside pot and rhizobox experiments under controlled greenhouse conditions, field experiments under different climatic and agricultural conditions will guarantee generally admitted results with high practical relevance. Beside classical chemical and biological analysis, molecular biological methods will be used to trace microbial inculcates and to monitor the impact of bio-effectors on soil microbial community structure. Marked evaluation and the development of marketing strategies will be done as well. The consortium of Central and East European participants represents a sufficient range of different climatic zones for meaningful field experiments and the whole range of analytical expertise necessary to conduct this ambitious project. Climatic variability within the group of participants also allows for an assessment in the context of global change both with respect to adaptation and remediation.
Networking and cooperation at the European scale is an essential tool within this project. First of all this concerns the development of a joint procedure for standardised testing and the subsequent realisation of joint green-house and field experiments to test selected bio-effectors under different European climate conditions. Specific knowledge and analytical expertise available by single partners will be made available for all participants.
This project will strongly support the preservation of natural resources by utilisation of bio-effectors’ potential to reduce fertiliser and pesticide input in intensive agriculture. Reduced input of agrochemicals will minimise the risk of environmental pollution and increase food safety. The resulting reduction of fossil energy input into agriculture (CO2-balance) together with reduced gaseous nitrogen losses (N2O) will reduce direct and indirect greenhouse gas emission from agriculture (climate impact). Within organic and low input farming, bio-effectors will increase and stabilise yield levels. Replacing expensive agrochemicals by cost-saving bio-effectors at a constant or even increasing yield level will increase the profitability of agricultural production. The direct collaboration of small and medium scale enterprises ensures development close to the market and direct economical impact for European business.
Hence, bio-effectors are expected to have a great economical and ecological impact on European and international agriculture at different levels of intensity.
The project consists of partners from the following EU- and non-EU-countries: Czech Republic, Germany, Hungary, Italy, Romania, Russia, Thailand, The Netherlands, Turkey and Indonesia. This includes both Universities and Medium and Small Scale Enterprises.
Currently the consortium has no external funding.
Coordinator: Prof. Dr. Torsten Müller, Universität Hohenheim (330c), Inst. of Plant Nutrition, Stuttgart, Germany