Biochar actions for the mitigation of plant abiotic stress

Abstract

Abiotic stresses are the dominant constraints to successful crop production in the modern era. Over the past few decades, researchers have devised various techniques to ease the effects of abiotic stresses on crop plants. Biochar is a vital eco-friendly biostimulant that mostly increases crop production and alleviates the adverse effects of different abiotic stresses. It improves crop yield as a fertiliser and soil quality as a soil conditioner. Biochar amendment in the soil is gaining popularity these days. This is because it improves the physio-biochemical and biological properties of soil. Biochar enhances abiotic stress tolerance as well as growth and yield of plants by modulating ionic homeostasis, photosynthetic apparatus, antioxidant machineries, reducing heavy metal accumulations and oxidative damages. However, the stress-relieving roles of biochar have not been thoroughly assembled. This review summarises current reports of biochar application and discusses the potential roles of biochar amendment in soil for crop growth and production under stress and non-stress conditions. This review also covers the possible mechanisms for how abiotic stress mitigation is accomplished in plants and the limitations and prospects of biochar application in agriculture.

Organic Amendments for Mitigation of Salinity Stress in Plants: A Review

“…BC is a carbon-rich organic substance with a porous structure, a wide surface area, and a high ion exchange ability that improves the physical qualities of agricultural soil [ 83 , 84 ]. A number of studies found that BC application improves the different physio-biochemical processes such as photosynthesis, hormonal and enzymatic activity in plants and decreases the harmful effects of salt stress on plants ( Figure 1 and Table 2 , [ 5 , 22 , 83 , 84 , 85 ]).…”

“…Soil salinity is a key abiotic stress that interferes with crop growth, development, and yield through altering morphological, physio-biochemical, and molecular processes [ 1 , 2 , 3 , 4 , 5 , 6 ]. Every year, 1–2% of cultivable land is reduced due to soil salinity and worldwide, about 800 million hectares (23%) of total arable lands are affected by soil salinity [ 7 , 8 ].…”

“…To reduce excess soil salinity, plant scientists are employing techniques such as sub-soiling, mixing sand, seed bed preparation, and salt scraping, as well as modern agronomic practices, hydrophilic polymer, gypsum, sulfur acids, green manuring, humic substance, farm yard manures, irrigation system, and salt-tolerant crops [ 19 , 20 , 21 , 22 ]. Recently, different organic amendments such as the application of vermi-compost (VC), vermi-wash (VW), biochar (BC), plant growth promoting rhizobacteria (PGPR), and bio-fertilizers (BF) are being used widely to ameliorate the negative consequences of soil salinity [ 5 , 6 , 23 , 24 , 25 , 26 ]. For instance, VC enhances morphological traits, chlorophyll content, antioxidant enzyme activities, and improves salinity tolerance of maize plants [ 27 ].…”

“…For instance, VC enhances morphological traits, chlorophyll content, antioxidant enzyme activities, and improves salinity tolerance of maize plants [ 27 ]. Several studies showed that BF and BC enhance plant growth progressions under salinity stress by improving antioxidant enzyme activities, and reduces oxidative damage in different plants [ 5 , 28 , 29 ]. In addition, the inoculation of PGPR under salt stress accelerates microbial population and gene expression in the rhizosphere, boosts biomass production and enhances the salt tolerance of different plants [ 6 , 30 , 31 ].…”

Biochar and fertiliser interactions in crop and pasture production

“…This Special Issue has also selected articles on how biochar and fertiliser can increase soil health and crop yields and overcome soil constraints such as acidity, salinity, drought, low fertility and remediation of contaminated soils. Imran et al (2022) wrote a review paper stating that biochar is a soil conditioner and an eco-friendly biostimulant that mainly increases crop productivity, alleviates adverse effects of abiotic stresses and improves crop yield. Biochar amendment is gaining popularity because it improves soil's physiochemical and biological properties.…”