Microbial inoculants improve nutrients uptake and yield of durum wheat in calcareous soils under drought stress in the Mediterranean region

ABSTRACT

Despite some evidence in greenhouse experiments, the benefits of Bacillus subtilis and Trichoderma asperellum on nutrients uptake by plants under field conditions are unknown. This work aims to study the effect of these microbial inoculants on durum wheat nutrition and yield under Mediterranean conditions where soils may lead to micronutrients and phosphorus deficiencies and where drought may promote low use efficiencies of applied fertilizers. To this end, three experiments were performed in two growing seasons. B. subtilis increased the uptake of nitrogen, phosphorus, and manganese relative to other treatments in the experiment carried out in the first growing season involving two experimental sites. The increased phosphorus uptake was attributed to the increased activity of alkaline phosphatase. In this first season, T. asperellum increased acid phosphatase activity without effect on P uptake and decreased the P to Zn molar ratio in grains, thus improving grain quality for human consumption. In the second season, the effects of microbial inoculants were less evident possibly due to favourable environmental conditions for crops (higher water availability) or phosphate fertilization. Results evidenced that B. subtilis can be effective improving the development and nutrient uptake of durum wheat under more stressful conditions, such as drought stress.

KEYWORDS:

• Bacillus subtilis
• Trichoderma asperellum
• nitrogen
• phosphorus
• zinc

Acknowledgements

The authors thank the Agricultural Research Service of the University of Seville (SIA) for technical assistance and access to experimental facilities, and the Institute of Research and Training in Agriculture and Fisheries (IFAPA) of the Regional Government of Andaluca for providing access to experimental sites.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03650340.2022.2146099

Additional information

Funding

This work was funded by the Spanish Ministry of Economy, Industry and Competitiveness and the European Regional Development Fund of the European Union through the National Research, Development and Innovation Program (Plan Estatal I+D+i, Project AGL2017-87074-C2-1-R).