Determination of Labile Phosphorus in Soil: A Low-Cost Proposal Using Digital Images

• Grant number: 24/08182-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• Status: Discontinued
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Arnaldo Alves Cardoso
• Grantee: Stella Sales Macedo
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated scholarship(s): 25/04704-0 - Studying the ultrasound-assisted extraction of phosphate in soil using the portable ultrasonic equipment UTR 200, BE.EP.IC

Abstract

This proposal seeks to develop a method to provide rapid, in situ data on labile phosphate levels in the soil. Knowledge about the availability of macronutrients in the soil is crucial for farmers to manage the use of fertilizers efficiently. Lack of nutrients can result in low agricultural productivity, and excess can cause economic losses and environmental impacts. The project proposal will seek alternative procedures for collection, sample preparation, and analytical determination of labile phosphorus in the soil. The phosphate quantification reaction, which leads to the formation of molybdenum blue, is convenient to be handled digitally. The reaction conditions will be evaluated to find the best conditions for using digital images as an analytical signal, quantified through the RGB color space using a smartphone to capture the images. These images will later be processed by the ImageJ software to seek the best condition for determining the best sensitivity and low detection limit. The aim is to carry out a study on using ultrasound in the treatment of soil samples and compare it with reference methods. Sample treatments will be made with certified soils containing different compositions of organic material, iron, and aluminum. At the end of the project, it is expected to define conditions for soil collection and sample treatment that can be used in combination with the proposed method for determining labile phosphorus.