Role of vesicular arbuscular mycorrhizae (VAM) in meeting phosphorus needs of important crops and cropping systems

The impact of three vesicular arbuscular mycorrhizae (VAM) cultures with or without inorganic P was studied in rainfed maize–wheat and soybean–wheat crop sequences in a P deficient acid Alfisol. Application of these 3 VAM cultures [Glomus mosseae-developed by CSK HPAU, Palampur; Glomus intraradices-developed by The Energy and Resources Institute (TERI), New Delhi; Glomus mosseae-developed by Indian Agricultural Research Institute (IARI), New Delhi] alone or with 25 to 75% of recommended P₂O₅ dose based on soil test crop response (STCR) precision model along with 100% of recommended N and K, gave significantly higher grain/seed and straw yields and soil nutrient build up over control. Above treatment enhanced yields consistently and significantly with increasing applied P from 25 to 75% of recommended P₂O₅ dose. It can be inferred that application of either of 3 VAM fungi cultures with 75% P₂O₅ dose can economize yield targeted fertilizer P dose by about one fourths of P requirement in rainfed maize–wheat and soybean-wheat crop sequences without impairing soil fertility in P deficient acid Alfisol.