VAM Fungi Spore Populations in Different Farming Situations and Their Effect on Productivity and Nutrient Dynamics in Maize and Soybean in Himalayan Acid Alfisol

Abstract

To assess the effect of five vesicular arbuscular mycorrhizae (VAM) isolates of Glomus mosseae screened out from different farming situations, two pot experiments were conducted on maize and soybean in a phosphorus (P)–deficient Himalayan acid Alfisol. There was variation in VAM spore populations of Glomus mosseae isolates screened out from maize harvested fields, soybean fields, vegetable fields, tea orchard, and citrus orchard. Glomus mosseae isolate from vegetable-based cropping system exhibited maximum root colonization at flowering in maize (32%) and soybean (28%), followed by Glomus mosseae isolate from soybean fields, and exhibited the lowest in Glomus mosseae isolate from tea farm. Glomus mosseae isolate from vegetable-dominated fields was at par with Glomus mosseae isolate from soybean-based cropping system, again resulting in significantly high root biomass, nitrogen (N)–P–potassium (K) uptake, and grain and straw productivity both in maize and soybean crops besides the greatest Rhizobium root nodule biomass in soybean. There was a considerable reduction in soil fertility with respect to NPK status over initial status in pot soils inoculated with Glomus mosseae isolate from vegetable-dominated ecosystem, thereby indicating greater nutrient dynamics by this efficient VAM strain in the plant–soil system and greater productivity in a P-deficient acidic Alfisol. Overall, VAM isolates from different cropping systems and farming situations with variable size and composition of VAM mycoflora resulted in differential effects on growth, productivity, and nutrient dynamics in field crops. Overall, Glomus mosseae isolates from vegetable and soybean fields proved to be superiormost in terms of root colonization, growth, and crop productivity as well as nutrient dynamics in above study. Thus, isolation, identification, and selection of efficient VAM strains may prove as a boon in low-input intensive agriculture in P-deficient Himalayan acidic Alfisol.