Effect of Silicon based Fertilizer and Biochar from Crop Residues on Dry Matter Accumulation and Si Uptake by Rice Crop in Central Vietnam

Background: Silicon (Si) has been considered a beneficial element for many plants. Si-rich biochar (Sichars) from rice husk or peanut shell have been suggested to be a potential source of bioavailable Si for Si-accumulator plants. Our study aimed to assess the Si-fertilization efficiency from chemical fertilizer and rice husk and peanut shell biochars on rice dry matter and shoot Si uptake. Methods: Pot trials were conducted in two crop seasons in 2023 (from February to April - spring season and from May to July- summer season) in the close net house. Treatments included 1 treatment with pure soil (control), 4 treatments with Si and N–P–K fertilizers and 6 treatments with biochar amendments and N-P–K fertilizers. These pot experiments were designed in the randomized complete block (RCBD) with 4 replications. Result: Shoot dry matter increased from 35.6 to 66.7% compared with control in different rates of Si fertilizer application and was also found the highest values in RHB and PSB at 15 g/kg soil application. Different Si and biochar application rates had a significant effect (P less than 0.05) on Si uptake by rice shoot. Therefore, Si-rich biochar considers as potential material for providing available Si to maintain the required level of available Si in soil and plant for healthy and high crop production.