Mitigating Drought Stress Effects in Arid and Semi-Arid Agro-Ecosystems through Bioirrigation Strategies—A Review

Drought stress is most alarming and destructive among the abiotic stresses that increased in intensity in recent years affecting global food and nutritional security. The main resource limiting global agricultural productivity is water. The previous two decades have seen a surprising amount of study reports on genetically modifying plants to increase their ability to withstand drought, but actual progress has lagged behind expectations. Applying bioirrigation techniques in drought-prone areas might be a workable alternative strategy. It does apply to the usage of living things or biological creatures, such as potential microorganisms that can move soil moisture from a zone with enough water to plants that are drought-stressed through the modification of agricultural microclimate using agronomic strategies. Potential microorganisms include Gram+ and Gram− bacterial consortiums, as well as plant-growth-promoting rhizobacteria (PGPR). In addition to PGPR, the utilization of soil macro-fauna in agriculture, such as earthworms, lugworms, termites, etc., can be utilized and explored in the near future towards bioirrigation. Earthworms and other macro-fauna are abundant in soil, digging deep burrows in the sediment and providing aeration to the plants. PGPR evolved with plant roots to enhance plant resilience under biotic and abiotic stresses. Benthic microorganisms, which include bacteria and microalgae, for instance, have a 70–80% higher water-holding capacity. Through research findings, these benthic microorganisms can be successfully identified and used in agriculture, and they may prove to be a cutting-edge method to increase plant-water-use efficiency. Similarly, plant roots of legume plants act as bioindicators under drought-stress conditions. These new developments make a significant contribution to addressing the problems of food security that come with changing climate. This review article offers information on bioirrigation techniques, their potential, estimating techniques, etc. Overall, this article goes into detail about how bioirrigation techniques aid crop plants in overcoming drought stress. Future research should focus on creating the most appropriate and effective microbes, dealing with the problem of delivery systems, and evaluating potential organisms in the field for microbial formulations to improve plant performance under drought stress and significantly lower yield losses in drought-affected areas.