Studies on Vesicular Arbuscular Mycorrhizae VAM in meeting phosphorus needs of okra wheat sequence in Typic hapludalf

Abstract

newline The present investigation entitled Studies on Vesicular Arbuscular Mycorrhizae (VAM) in meeting phosphorus needs of okra-wheat sequence in Typic hapludalf was carried out in randomized block design with thirteen treatments replicated three times, during kharif 2005 and 2006 (okra as test crop)and rabi 2005-06 and 2006-07 (wheat as test crop) in the experimental Farm of Soil Science department,CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur. Four level of P (0, 50, 75 and 100 % based on STCR approach) in combination with three different VAM culture viz; local (Glomus Sp.), TERI (Glomus introradices) and IARI (Glomus mosseae) were tested with okra and wheat in comparison with control. Soil samples taken from surface soil (0-15cm), after the harvests of okra as well as wheat during both the years of experimentation were analyzed for available NPK, DTPA extractable micronutrients (Fe, Cu, Zn and Mn) and soil pH using standard methods of analysis. Different forms of Phosphorus were also determined in the soil samples collected at the termination of entire experiment. Yield attributes, crop quality, root mass, root mass density, economic yield and nutrient uptake of okra as well as wheat increased significantly and consistently with increase in P application from 25 to 75% of recommended P2O5 along with VAM culture and highest value was recorded with application of 100 % P2O5 as per STCR approach.. Higher value of VAM infection was recorded in treatment comprising 75 % P2O5 application as per STCR approach along with VAM culture. Significant improvement in the status of available NPK was recorded over the control. However, within certain treatments differences were not significant. In case of P, its status improved from initial value in treatment comprising 75 % and 100 % P2O5 application as per STCR approach. Phosphorus fractions varied in the order Fe-P gt Al-Pgt Ca-P gt saloid-P and these fractions have shown significant and positive correlation with available P, marketable fruit yield of okra, P u