Abstract
Two acid-producing bacteria ( Agrobacterium radiobacter and Agrobacterium sp.) and/or an ectomycoorhizal fungi ( Laccaria laccata) were inoculated in the rhizospheres of beech and pine seedlings, in lysimetric devices in geenhouse. Plants were grown on sand mixed with rock phosphate and phlogopite (iron-magnesian mica). Influence of these micro-organisms on plant growth, plant nutrition and plant exudation was observed after two years. Agrobacterium radiobacter, or Laccaria laccata, root inoculation increased beech growth and nutrient uptake (P, Ca, K, Fe, Mg) by beech seedlings. But dual inoculation by both micro-organisms had no significant effect on plant growth and plant nutrition. With pine seedlings, the only growth and nutrient uptake promoting effect was observed with Agrobacterium sp. inoculation and concerned only the root system. Bacterial inoculation increased the amount of organic acids (malic, lactic, fumaric, citric) released in the rhizosphere, which promoted mineral element solubilization and, thus, plant mineral nutrition. Mycorrhizal plants did not released greater amounts of organic acids than non mycorrhizal plants. The effect of Laccaria laccata on beech growth and nutrition could be attributed to a better soil exploration, as shown by the increased rhizospheric volume.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call