Phosphate fertilization regulates arbuscular mycorrhizal symbiosis in roots of soybean (Glycine max L.) cultivars in a humid tropical soil

Abstract

<p>The effect of phosphate fertilization on arbuscular mycorhizal symbiosis and grain yields of soybean cultivars was investigated on P deficient soil. A two-year field study (2017-2018) consisting of two soybean cultivars (TGx 1448-2E and TGx 1440-1E) and three phosphate rates [0, 20 and 40 kg P<sub>2</sub>O<sub>5</sub> ha<sup>-1</sup>) was laid out in a randomized complete block design with three replications. The results showed that P fertilization significantly (<em>p</em> < 0.001) reduced AMF root colonization of both cultivars in the two cropping years. The arbuscular, vesicular, internal hyphae and total colonization in the root cortex of the soybean cultivars were significantly (<em>p</em> < 0.001) reduced with high P (40 kg) application. However, moderate P (20 kg) promote AMF symbiosis in roots of ‘TG x 1448-2E‘. Dry mass (root and shoot), P uptake and grain yield of the soybean cultivars were significantly (<em>p</em> < 0.001) increased with increasing P ferilization. There was a strong linear relationships between root colonization and total dry matter mass (r = 0.81), P uptake (r = 0.81) and grain yield (r = 0.85). Thus, it could be concluded that moderate P fertilizer application is needed to promote mycorrhizal symbiosis in soybean and sustainable crop production in humid tropical soil.</p>