Investigating the potential of nanobonechar toward climate-smart agriculture.

Extreme climates and the unpredictability of the weather are significant obstacles to agricultural productivity. This study is the first attempt to explore the capacity of nanobonechar (NBC) for promoting climate-smart agriculture. A pot experiment was performed on maize (Zea mays L.) under a deficit irrigation system (40, 70, and 100% irrigation rates) using different soil application rates of the NBC (0, 0.5, 1, and 2% wt/wt). Additionally, the CO2 -C efflux rate and cumulative CO2 -C were measured in an incubation experiment. The results indicated the best performance of the 1% NBC treatment under a 70% irrigation rate in terms of the fresh and dry weights of maize plants. Total PO4 3- and Ca2+ were significantly higher in the plants grown in the NBC-amended soil as compared to the control, showing a gradual increase with an increase in the NBC application rate. The improved productivity of maize plants under a deficit irrigation system was associated with enhanced water-holding capacity, organic matter, and bioavailability of cations (Ca2+ , K+ , and Na+ ) and anions (PO4 3- and NO3 - ) in the soils amended with NBC. The CO2 -C efflux rate and cumulative CO2 -C emissions remain higher in the NBC-amended soil than in the un-amended soil, pertaining to the high contents of soil organic matter emanating from the NBC. We conclude that NBC could potentially be used as a soil amendment for promoting maize growth under a water stress condition.