Production of Rhizobium Inoculants for Lupinus nootkatensis on Nutrient-Supplemented Pumice.
The use of the legume Lupinus nootkatensis as a pioneer plant to fight soil erosion and to reclaim eroded soils in Iceland has been under development for a few years. Production of a robust, low-cost bacterial inoculant was therefore a prerequisite for the extended use of this plant. Volcanic pumice is a naturally expanded mineral which is available in vast amounts in Iceland. It was tested as a carrier for solid fermentation of Rhizobium lupini. Nutrient-supplemented pumice containing a small percentage of peat and diatomaceous earth and kept in sterile plastic bags promoted good growth of the bacteria. Viable-colony counts remained stable at 10 to 10/g for at least 35 weeks when the carrier was stored at 22 degrees C. The pumice-based inoculant had good storage and handling properties and could be mixed directly with the seeds during the sowing process. When seeds of L. nootkatensis were sown manually into nutrient-poor eroded sandy soils, about 56% of the first-year plants were successfully nodulated.
Einarsson
S
S
Department of Biotechnology, Technological Institute of Iceland, and Agricultural Research Station, Keldnaholt, IS-112 Reykjavík, Institute of Biology, University of Iceland, IS-108 Reykjavík, and Soil Conservation Service of Iceland, Gunnarsholt, IS-850 Hella, Iceland.
Gudmundsson
J
J
Sverrisson
H
H
Kristjansson
J K
JK
Runolfsson
S
S