Biochar or pyrogenic carbon, obtained from thermo-chemical conversion of biomass in an anaerobic or oxygen limited environment has been in use in agriculture since long back to Neolithic era. Its unique soil ameliorating properties, render it suitable for environmental remediation as well as sustainable crop production. It improves soil physicochemical properties and plant nutrient availability, facilitates biodiversity, and reduces emission of greenhouse gases, thereby subsiding global warming. Application of biochar reduces soil erosion, improves soil hydrological properties, and soil microbial dynamics. It has synergistic effects on plant growth, disease-pest resistance, and crop yield per unit area and time. Due to its soil ameliorative effects, and soil and water conserving ability, it can very well be used in organic farming, pemaculture, dryland farming, conservation agriculture, and land remediation. Cheaper production cost, simple and easy pyrolytic technologies, easy availability of feedstock and bio-wastes in many developing countries and its long-term effects in soil not only build up soil carbon pool but also help support small and marginal farmers in resource-rich but economically deprived countries for sustainable agriculture and environment. In this review, efforts have been made to elucidate various methods of biochar synthesis, its characteristics and effects on soil properties, and plant growth and development, its role in sustainable agriculture and remediation of the environment.

Fly ash (FA) is the 80% of coal burnt by-product of thermal power plants (TPPs), its disposal in landfills causes environmental and health issues. The amount of FA production is increasing continuously to fulfil the worldwide energy for demand, which possibly never find a practically safe method for FA dumping. Its fine particle size disperses in the air and causes air pollution and water pollution is resulted due to slurry erosion from FA dumps and contamination by leachate. Health issues and environmental concerns due to fly ash landfills/dumpsites can be prohibited by covering with phytoaccumulator plant species. Limitations of plant growth in FA includes alkaline pH, contain metals such as Cr, Cd, As, Hg and Pd, toxic level of B, pozzolanic properties of FA and lack of microbial activity. Generally, the phytoremediation process is slow therefore, to accelerate the phytoremediation process FA require organic amendments and bio-fertilizers. This article focuses on the role of naturally occurring plants in stabilization of FA dumpsite and physiochemical changes in FA. This review summarises the different holistic approaches of rehabilitations of FA landfills and also compiles how to convert FA landfills into useful landfills for bioenergy productions. Utilization of organic matter and industrial waste has been proved to provide essential nutrients for plant establishment and heavy metal accumulation. The outcomes of this learning are beneficial for classifying site-specific ecological restoration of FA landfills through holistic approach.