Tropical soil fertilization with nitrate-rich-biochar

• Grant number: 24/01673-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): March 01, 2024
• Effective date (End): February 28, 2025
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Ricardo César Aoki Hirata
• Grantee: Mariana Rodrigues Sobral
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 20/15434-0 - SACRE: integrated water solutions for resilient cities, AP.TEM

Abstract

Oxisol is a typical tropical soil and the most common one in the state of São Paulo. It is widely used for agriculture; however, it is acidic and poor in nutrients, demanding significant fertilizing applications. One potentially sustainable alternative is to reuse biochar previously used for nitrate removal from groundwater as a slow-release fertilizer. This material is a potential source of nitrogen and potassium from the sugar cane bagasse's original composition. This solution has the advantage of recirculation the nitrogen, and the slow release might decrease the potential for leaching to groundwater. The biochar samples will be characterized, and their capacity to release the Oxisol nutrients will be evaluated. Column tests will be performed under different conditions, such as different pH and flow rates. The processes occurring, such as nitrogen release from the biochar and transformations, will be assessed by determining nitrate, nitrite, ammonium, and organic nitrogen in the percolated solutions. The changes in soil properties will also be evaluated before and after the leaching process.