Biochar is considered as a potential substitute for soil organic matter (SOM). Considering the importance of biochar, the present review is based on the different benefits and potential risks of the application of biochar to the soil. Biochar addition to low organic carbon soils can act as a feasible solution to keep soil biologically active for the cycling of different nutrients. The application of biochar could improve soil fertility, increase crop yield, enhance plant growth and microbial abundance, and immobilize different contaminants in the soil. It could also be helpful in carbon sequestration and the return of carbon stock back to the soil in partially combusted form. Due to the large surface area of biochar, which generally depends upon the types of feedstock and pyrolysis conditions, it helps to reduce the leaching of fertilizers from the soil and supplies additional nutrients to growing crops. However, biochar may have some adverse effects due to emissions during the pyrolysis process, but it exerts a positive priming effect (a phenomenon in which subjection to one stimulus positively influences subsequent stimulus) on SOM decomposition, depletion of nutrients (macro- and micro-) via strong adsorption, and impact on soil physicochemical properties. In view of the above importance and limitations, all possible issues related to biochar application should be considered. The review presents extensive detailed information on the sustainable approach for the environmental use of biochar and its limitations.

Conventional tillage (CT)-based agriculture is known to be ecologically indiscreet, economically and environmentally unsustainable, and leads to the degradation of soil and the environment in the Indo-Gangetic Plain (IGP). The surface seeding (SS) method was introduced to manage agro-ecosystems for sustaining productivity and increasing farmers’ profits, while sustaining the natural resources. Here, we conducted a systematic literature review on SS of wheat reported in the IGP, with the aim to cover the concept of SS, its impact on wheat yield, soil properties, and the environment, with the potential benefits and constraints. The major findings are: (i) an SS-based rice–wheat system improves productivity (∼10%) and profitability (20–30%),while employing a lesser amount of irrigation water (15–30%) and energy input (20–25%) compared to a conventional system; (ii) an SS-based system is more adaptive to extreme climatic conditions, reduces the carbon footprint, and increases crop production; (iii) an SS approach enhances soil health by virtue of increased soil organic carbon and improved soil aggregation, as well as soil, water, and energy conservation; (iv) SS consisting of no-tillage with substantial crop residue retention offers an alternative to crop residue burning. Strong policies/legislation are required to encourage SS of wheat, in order to limit residue burning, and provide farmers with carbon credits in exchange for carbon sequestration and reduced greenhouse gas emissions.

Heavy metal contamination in agricultural field is a challenging aspect globally. Various methods are employed to address the issue; biochar among the most cost-effective and promising one. Our study encompasses biochar preparation from Parthenium, a noxious weed of agricultural field, and its subsequent modification using ferric chloride and orthophosphoric acid. Results revealed that more than 20% reduction of Pb, Cd and Ni in Rice roots under 5 and 7.5 t ha-1 biochar treatments. Moreover, greater than 30% reduction of abovementioned heavy metals in rice grains is also noted in 10 t ha-1 biochar application rates. So, it can be concluded from our study that biochar application to a metal contaminated soil can be a promising approach to reduce metal accumulation in different parts of rice and subsequently addressing the adverse effect of it in human body.