Inoculation of arbuscular mycorrhizal fungi improve soil chemical properties, growth and symbiotic N2 -fixation in soybean (Glycine max L.) cultivars under field condition with low phosphorus availability

Abstract

Arbuscular mycorrhizal fungi (AMF) play an important role in nutrition of most plants as well improving soil fertility. The present study investigated the effects of different AMF isolates (Funneliformis mosseae, Rhizophagus intraradices and Claroideoglomus etunicatum) and control on soil chemical properties, growth and nitrogen (N2 ) fixation in two soybean cultivars (TGx 1448-2E and TGx 1440-1E) in phosphorus (P)-deficient soil. The study was laid in split plot in a randomized complete block design with three replications. The results showed increased root colonization (up to 76%) with AMF inoculation compared to uninoculated control. The inoculation of the AMF isolates enhanced the growth parameters, nodulation and dry weights, which resulted in increased number of pods, 100-seed weight and seed yield. More pronounced effects were observed with F. mosseae and R. intraradices inoculation compared to C. etunicatum. In addition, similar trend was observed for P and N content in the plants as well the N2 fixation activities, which resulted in increased total N fixed in both cultivars (up to 27.9 and 27.4 kg ha-1 respectively). After harvest, the results showed improved soil fertility in terms of soil N, available P, soil pH, organic carbon as well as exchangeable cations (calcium, magnesium, potassium and sodium) with AMF inoculation. TGx 1448-2E inoculated with F. mosseae gave the highest seed yield (1,773 kg ha-1). The findings from this study suggest that R. intraradices or F. mosseae could be used to enhance N2 -fixation, soil fertility and productivity of soybean in phosphorus-deficient soils.

Keywords

• arbuscular mycorrhizal fungi
• soil phosphorus
• relative ureide abundance
• soil fertility
• soybean productivity