Saline soils have a negative effect on plant growth and development. These soil types are a major limiting factor in crop growth worldwide. As a matter of fact, it is estimated that a total of 20% cultivated lands and 33% irrigated agricultural lands are afflicted by high salinity. Soil salinity limits plant growth due to the presence of soluble salts in the soil. These soluble salts hold watertight and the plants are not able to extract them. As a result, the build-up of excess water brings dissolved salts into the root zone; therefore, causing a concentration of these salts which reduces the amount of available water, thus restricting the amount of water the crop can extract.
There are certain conditions that account for soil salinity, one being the presence of soluble salts in subsoil or groundwater. Another condition that might cause soil salinity, is a higher water table. High water tables cause soluble salts to move into the root zone of crops. However, the most common factor is the presence of excessive salts in the soil which results in high electrical conductivity. Electrical conductivity is defined as the measurement of soluble salts in the soil. As the concentration of soluble salts increases, the electrical conductivity of the soil additionally increases.
All soils contain some water-soluble salts, however, a concentration of these salts suppresses the plants’ ability to grow. Crops grown in saline soils suffer due to high osmotic stress, nutrition toxicities, poor soil physical conditions and reduced crop productivity. There have been several strategies developed in order to decrease the toxic effects caused by high salinity, including plant genetic engineering or even the use of plant growth-promoting bacteria. Microorganisms could play a significant role in the remediation of these areas if we exploit their unique properties such as their tolerance to saline conditions. It has been seen that soils inoculated with arbuscular mycorrhizal fungi (AM) have improved plant growth under salt stress. These beneficial microorganisms colonize the rhizosphere/endorhizosphere of plants and promote the growth of plants through various direct and indirect mechanisms.
Plant-associated microorganisms can play an important role in conferring resistance to abiotic stresses like soil salinity. HumaTerra Regen Ag uses microbial biostimulants to alter the soil’s structure, thus enhancing pore space. The enhanced pore space allows roots to get down into the soil and break it up, creating better drainage enabling salts to accumulate in the rooting areas. Microbial biostimulants will strengthen the clay-humus complex. This will help sequester the salts that are present in concentrated quantities, hence reduce the toxicity to plants. When soils are high in salts the clay particles have the same charge at their surface, this means that in the presence of water the soil clay colloid will disperse and the soil structure will collapse. Microbial biostimulants contribute to altering the clay surface’s electrical properties, which help to preserve the soil’s structure. In order to improve crop productivity, it is important to address the soil’s health through plant and soil microorganism interaction.