Phosphate Solubalising Bacteria

Some bacteria like Aspergillus awamori have the capacity to solubalise the phosphates fixed in soil. It must be recalled here that most of applied phosphorus is fixed in soil, and a small part of it is available to plants every year as labile phosphorous. When such bacteria are grown in large quantity in soil during the plant growth they release large quantities of phosphorus from fixed sources and make it available to crop roots. Recently such bacterial fertilizers are also made available in the market. Phosphate solubalising bacteria have potentiality to solubalise 10 - 20kg phosphorus per hectare - there by avoiding the necessity to apply phosphatic fertilizers.

Vesicular Arbuscular Mycorrhizae (VAM)

Mycorrhizae is a type of fungus living in association with plant roots. Hyphae of such fungi are found in between cortical cells of roots and protrude outside the roots also. The Mycorrhizae lives in close association with roots without disturbing their normal physiology. These hyphae form swollen vesicles or finely branched mass of hyphae called arbuscules. VAM is also known for release of fixed phosphorous in soils, as it can secrete special p-solubalising hormones. VAM culture is being commercially used in many crops to avoid use of phosphatic fertilizers.