Exploration of novel rhizospheric yeast isolate as fertilizing soil inoculant for improvement of maize cultivation.

Abstract

Chemical input in agriculture is a common practice but makes a serious impact to the environment. In this context, soil isolates having multiple plant growth-promoting (PGP) attributes have been studied. The isolates were tested for their PO4 and Zn solubilization, indole-3-acetic acid (IAA) production and N2 fixation ability. The selected isolate SSm-39 was characterized to molecular level. The isolate SSm-39 was applied to maize cultivation in various combinations with chemical fertilizers. Also, the chemical and microbial status of soil, its effect on maize growth and yield were investigated. Isolate SSm-39 found most suitable for its PGP attributes and identified as Candida tropicalis. The inoculant (100%) with reduced dose of chemical fertilizer (T5) application notably increased the growth and yield performance of maize. It has improved grain quality by 85% as indicated by carbohydrate and protein content, in comparison to uninoculated control (T3). Soil nutrient status was found to increase twofold with T5 treatment compared with T3 treatment. Enhanced soil nutrient quality supported microbial growth and diversity, thus accelerating soil enzymatic activities. The results validate the multiple PGP traits of C. tropicalis SSm-39, advocating reduction of chemical fertilizer for maize cultivation.