Biochar-assisted agriculture: from healthy soil to healthy plants

Plant health is conceived as the plant capacity of resource efficient production, of tolerance to abrupt stresses by extreme weather events, of bio-control or bio-defense of soil-borne pathogens and of safe synthesis of functional compounds for food quality and human nutrition. Biochar soil amendment provided quick restoration of soil organic matter, soil structure build-up and stabilization of toxic metals and organic pollutants in soil, benefiting safe growth of crops. Utilization of biochar for blending mineral nutrients creates slow releasing fertilizers so as to increase nutrient use efficiency and reduce the fertilizer dosage while supplement OC and minor elements to soil. Moreover, use of biochar for co-composting animal wastes to produce novel biochar-based composts is shown a useful application of biochar in organic agriculture. In addition, biochar use in anaerobic digestion and as sorbent in waste water and waste slurry is being explored in rural sector. As a particular case for rice crop production, biochar from rice residue to healthy paddy and rice can be managed into a closed loop: rice straw feeding cows and the manure into biochar-compost for soil amendment，rice husk biochar for biochar fertilizers and soil amendment, with more produced but less emitted. Biohcar could assist plant health with promoted growth and synthesis of functional compounds such as vitamin in vegetable plants and saponin in ginseng. Understanding the interaction of biochar-soil-plant interaction would help to find nature-based solutions to tackle the global dilemma of food security and climate change. The plant response both in biomass build-up and nutrition quality to biochar-based best management practices should be a research priority for crop production in agriculture facing the accelerated climate change and soil degradation over the globe.