What is it about?

In the present review, the individual and combined effect of compost, BC, and PGPR to alleviate drought stress in plants has been critically summarized. Moreover, research gaps and future research directions have been identified and discussed in depth.

Featured Image

Why is it important?

Plants are sessile organisms, frequently face unfavourable growth conditions such as drought, salinity, chilling, freezing and high-temperature stresses, inhibiting growth and development, and ultimately reducing crop productivity. Among these stresses, drought stress has been a major challenge for sustainable crop production and a hot area of research under the current climate change scenario. Organic amendments such as biochar (BC) and compost along with plant growth-promoting rhizobacteria (PGPR) could be a sustainable strategy to improve crop growth and productivity under drought stress environment. There are several reports about compost, BC, and PGPR application as a single or combined treatment to enhance crop productivity under drought stress. Compost and BC act as conditioners to improve soil physicochemical and biological properties thereby enhancing water holding capacity (WHC) and nutrient retention and availability to the plants. Both BC and compost also serve as carbon sources and suitable environment for PGPR and endogenous microbes to enhance their growth promotion activities under drought stress. PGPR alleviate drought stress via ACC-deaminase and P-solubilizing activities, production of phytohormones, secretion of organic acids, acting as biocontrol agents,etc.


Under drought stress, reduced growth and development of crops have been observed in many crops. For the sustainable management of drought stress, it is important to develop certain strategies that are efficient and low- cost to increase crop productivity. These resource management strategies include the integrated use of PGPR and organic amendments (compost, and BC). Figure 5 gives an overview of the impacts of drought stress on plants and its amelioration through economical, environment- friendly, and sustainable ways. These strategies help reduce environmental pollution due to the usage of various organic wastes for BC and com-post preparation and are environment- friendly. Numerous studies have confirmed their efficacy in improving the growth and yield of crops under drought stress. Algal BC is comparatively low in car-bon content, surface area and cation exchange capacity, but high in pH, ash, nitrogen, and extractable inorganic nutrients including P, K, Ca and Mg. Therefore, algal BC has properties that provide direct nutrient benefits to soils and crop productivity under drought stress. In the case of integrated use of PGPR, compost and BC, very few studies have been conducted under normal as well as under abiotic stress conditions such as drought stress. In the future, more rigorous studies are required to evaluate their additive effect during drought stress under field conditions. Moreover, in-sights into the mechanisms behind the interaction of PGPR and plants under drought stress need further investigation. For this elucidation, employing various state- of- the- art molecular approaches would help find out the mechanisms behind their synergistic effect.

Dr Allah Ditta
Shaheed Benazir Bhutto University Sheringal

Read the Original

This page is a summary of: Appraisal for organic amendments and plant growth‐promoting rhizobacteria to enhance crop productivity under drought stress: A review, Journal of Agronomy and Crop Science, May 2021, Wiley,
DOI: 10.1111/jac.12502.
You can read the full text:



The following have contributed to this page