Root-fungus symbiosis in agricultural crops selectively makes soil clays

摘要

In addition to the mutual association of roots and fungi, mycorrhizas benefit the general ecosystem through the production of soil clays. X-ray diffraction analyses showed that the fungus Glomus when inoculated onto barley, canola and alfalfa producedvarious types of potassium-deficient minerals (e.g., smectites) and slightly altered biotite, the K-rich mineral in the experiment. Non-inoculated plants produced mixed layer minerals, illite and left no biotite intact. The presence of K-poor clay minerals and unaltered biotite in inoculated samples implies selective K-extraction from some biotite grains to benefit plant growth and at the same time leaving unaltered biotite for future extractions. Symbiosis between fungus and plant roots (or mycorrhiza) is more efficient than roots alone in producing soil clays through the selective and efficient extraction of potassium ions from biotite