Properties of Nano-Amendments and Their Effect on Some Soil Properties and Root-Knot Nematode and Yield Attributes of Tomato Plant

The use of green nano-amendments is a promising approach for improving soil health and providing sustainable options to reduce root-knot nematodes (RKN) and thus increase yields. Therefore, the purpose of this research was to identify the characteristics of nano-amendments such as nanobiochar (nB), green nanobiochar (GnB), and magnetic nanobiochar (MnB) and their effect on the root-knot nematodes and tomato yield at levels of 3 and 6 mg kg −1 in sandy loam soil. The results showed that the GnB and MnB contain many functional groups (such as O-H, C=C, S-H, H-C=O, C-O, and H–O–H) and minerals (such as magnetite, ferrous sulfate monohydrate, and quartz), and they also had an elevated specific surface area. The application of the investigated soil nano-amendments significantly increased soil organic matter (OM) and microbial biomass carbon (MBC) and decreased the root-knot nematodes, playing a major role in increasing tomato growth. The highest significant values of OM and MBC were found in the soil amended by GnB at 6 mg kg −1 , with increases of 84.7% and 71.5% as compared to the control, respectively. GnB6 significantly decreased the number of root galls, the egg mass, and number of nematodes per 250 cm 3 soil by 77.67, 88.65, and 74.46%, respectively, compared to the control. Green nanobiochar was more efficient in accelerating the growth and yield components of the tomato plant. The addition of GnB is an effective strategy and an environmentally friendly technology to control plant parasitic nematodes and increase tomato yield. Therefore, the results recommend adding GnB at a rate of 6 mg kg −1 in sandy loam soil.