A very promising alternative farming system that is drawing more supporters is the combined use of legumes and rhizobia-based biofertilizers. However, with this approach, a number of questions are raised: Why are legumes so important in the context of sustainable agriculture? What are rhizobia and how are they related to legumes? What are biofertilizers and how do they benefit crop production?
TRUE Case study 22 at the Agricultural University of Athens uses legumes in crop rotations schemes in organic crops of non-legumes, aiming to increase soil fertility and ensure an adequate nitrogen supply to the crop despite the non-use of inorganic nitrogen fertilizers. This study will compare the environmental impact of organic and conventional cultivation systems and identify wider environmental effects when legumes are used in crop rotation schemes with non-legume vegetables.
Legumes are "smart" plants because they can utilize nitrogen from the atmosphere to cover their nutritional needs. Legumes do not need nitrogen fertilization as they form symbiotic relationships with rhizobia bacteria. Non-legume crops however need synthetic fertilizers to replenish the nitrogen removed from the soil. Case Study 21 at the AUA uses beans and grafting technique to obtain efficient rootstock/scion genotypes in terms of symbiotic nitrogen fixation and GHG emissions.
The soybean crop's high quantity and quality of proteins has led to growing global demand of soybeans for feed and food. Due to German consumer preferences, GM-free feed and organic soybean for human consumption are in high demand. Since cultivating GM-soybeans is not permitted in Europe, domestic production is a safe solution. So how can we better understand and identify agronomic factors for successful soybean cultivation to stabilize, optimize and expand soybean cultivation in Europe?
“You cannot grow soybean in Scotland”, was the advice recieved by Scottish researchers. Without evidence to support the conclusion, and like TRUE researchers we engaged optimistic seed suppliers to acquire the most suitable genotype. Driven by our interest in elite-rhizobia and -arbuscular mycorrhizal fungi (AMF) inoculum, we established a plot scale trial.