Zum einfluß der saatgutbeimpfung auf die luftstickstoffixierung und den ertrag der ackerbohne (Vicia faba L.)

Abstract

Summary The influence was tested of inoculating Vicia faba with Rhizobium leguminosarum — culture-solution, grown on loamy sand (pot cultures). The following aspects being investigated: fresh mass and dry mass of shoots, roots, and nodules; numbers of nodules; nitrogenase activity of the whole root (using the acetylene reduction assay). — In early spring, at low temperatures while sowing both the numbers of nodules and the amount of nitrogenase activity was significantly higher in inoculated plants than in plants not being subjected to treatment. The advantage of using the inoculation technique is also revealed; by crop parameters. — There is a decrease in the numbers of nodules with rising temperatures on the date of sowing. — In summer (July to September) cultivated broad beans were found lower numbers of nodules no advantage of inoculation could be found. The amount of crop of inoculated and noninocu-lated where with wild-rhizobia nodulated, was about the same in size. — Investigation of non inoculated broad bean grown in open land revealed that the first nodules emerged 6 d after germination (i.e., two weeks after date of sowing) with the process of reduction of acetylene already being under way. After 31 d the root system was well developed and nodulated; with a high degree of nitrogenase activity beginning after 45 d.