Role of Biofertilizers in Sustainable Agriculture Under Abiotic Stresses

Abstract

Sustainable agriculture development is a very important challenge that encounters the world nowadays as it requires increasing the productivity of plants with minimal disturbance of the environment. Plant growth is very susceptible to different conditions that affect its productivity and yield. These conditions could be divided into biotic (living) and abiotic (nonliving) stresses. Biotic stress includes interference from pathogenic microorganisms, insects, and higher animals, which include humans, while abiotic stress includes soil salinity, waterlogging, drought, high and low temperatures, wind, intense light, heavy metals, and inadequate or excessive mineral nutrients. Most of the abiotic stress factors could be attributed to different climatic changes which are considered the major reasons for regression of principal crop productivity. Plant species are surrounded by diverse beneficial microorganisms that dominate in their rhizosphere and have the ability to stimulate plant growth and protect them against different stress conditions. Different microbial activities have the ability to improve plant tolerance to biotic and abiotic stress conditions. The role of alleviation depends on the plant genus, the stress type, the microbial species, and the type of relationship between microorganisms and the plant. Microorganisms could enhance plant survival, growth, performance, and yield by several functions such as stimulating root growth by production of phytohormones, enabling water uptake to roots by production of polysaccharides in the root hair zone, improving plant nutrition by increasing nutrients through solubilization of phosphate, secreting siderophores for iron, and fixing dinitrogen, which is either associative or nonassociative. Using microbial inoculants is considered an important task in the next decades to counter abiotic stress in different regions.