Optimizing Rice Residue Biochar And Water Management To Improve Rice Yield And Decrease Uptake Of Toxic Metal(Loid)S

The overall objective of this proposed work is to determine the optimum combination of Si-rich rice residue (e.g., rice husk) and water management strategies to improve rice yield and simultaneously decrease both As and Cd contents in grain. We hypothesize that rice residue biochar synthesized at a moderate temperature of 250-300°C will create highly available Si source that most limits uptake of As and Cd under intermittently flooded soil conditions. Our preliminary work with charred and ashed rice husks has shown that rice husk burned at lower temperatures of ~250°C results in more plant-available Si that can help to decrease plant As concentrations. We have set the following objectives:Identify the optimum biochar temperature for rice husk and straw that maximizes Si plant-availability without adversely affecting other outcomes (e.g., pH, As availability).Quantify the performance of biochars under varying irrigation schemes in a pot study.Evaluate 3 optimized combinations of biochar and water management in a field plot study.