Organic compounds in root exudates of Miscanthus × Giganteus greef et deu and limitation of microorganisms in its rhizosphere bynutrients

This study was conducted to determine the composition of sugars and organic acids in root exudates of Miscanthus × Giganteus and to find out if microorganisms of the rhizospheric soil are limited by mineral nutrients. The following sugars and organic acids were determined in root exudates of this plant: glucose,saccharose,and acids such as succinic,propionic,citric,tartaric,malic,oxalic,ascorbic,acetic and fumaria Respiration of soil from rhizosphere of Miscanthus × Giganteus was found to be limited by N,K and Ca. Respiration rate after application of mineral compounds increased in following orther: nitrate calcium potassium ammonium,giving approx. 165,99,52 and 31 % increase compared to control. Further research is necessary to determine the role of plant nutrients from the point of their limitations for rhizosphere microorganisms,to broader very rare knowledges in this topic,especially for polluted soils to stimulate efficiency of phytoremediations.