Influence of biochar on growth performances, yield of root and tuber crops and controlling plant-parasitic nematodes

Abstract Root and tuber crops are important sources of food and provide income for millions of people worldwide besides an observed high demand for organically produced harvests. Hence, recent attention has been given to utilizing biochar, a carbon-rich material produced from the pyrolysis of organic materials, which improves soil structure, water-holding capacity, and nutrient availability, as an amendment to produce organic root and tuber crops. These effects are caused by the formation of organic coatings on the surface of biochar, which decreases hydrophobicity and increases the ability to retain nutrients, acting as a slow-release mechanism delivering nutrients dependent on plant physiological requirements. However, comprehensive studies on the impact of biochar application on root and tuber crop growth, productivity, and effectiveness in eliminating soil parasites have not been extensively studied. Thus, the purpose of this review is to explore the use of biochar and biochar-based soil amendments and their potential applications for improving the growth, yield, and efficacy of controlling parasitic nematodes in a wide range of root crops. Most of the studies have investigated the effects of biochar on cassava, sweet potatoes, and minor root crops such as ginger and turmeric. It has been observed that biochar application rates (5–20 t ha −1 ) increase the vine length and the number of leaves, tubers, and tuber weight. The addition of biochar demonstrates the ability to control plant-parasitic nematodes in a rate-dependent manner. While biochar has shown promising results in improving crop growth and yield of limited root and tuber crops based on a few biochar types, ample opportunities are around to evaluate the influence of biochar produced in different temperatures, feedstock, modifications and controlling parasitic nematodes. Graphical abstract