IMPROVEMENT OF CLOVER YIELD AND QUALITY BY INOCULATION WITH VAM FUNGI AND RHIZOBIUM BACTERIA

In pot trials clover yields were most positively influenced by inoculations with VA-Mycorrhiza fungi and Rhizobium bacteria. Highest improvements of shoot dry matter were obtained by a combined soil inoculation with VAM fungi isolate T6 and Rhizobium bacteria (Rhizob. leguminosarum biovar. trifolii) strain 105 in the treatments with rock phosphate. Under these conditions Persian clover (Trifolium resupinatum) showed a maximum yield. Shoot dry matter was improved up to 64 % compared with the uninoculated control. Thereby the quality - in terms of N-, P- and K-concentrations in the whole plants - remained almost unchanged. Mycorrhization, expressed as a per cent infection of root segments, developed more intensively in treatments with rock phosphate than with superphosphate fertilization. Clover plants inoculated with VAM isolate T6 reached higher P-uptake rates than with VAM isolate D 13. In addition, T6 also improved shooting and development of stems and blossoms of red clover (Trifolium pratense).