Use of amino acid- and humic substance-based biostimulant as a sustainable management tool for soybean cultivation in western São Paulo

• Grant number: 24/22006-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Fernando Shintate Galindo
• Grantee: Gustavo Chiari da Silva
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

The search for sustainable strategies to mitigate the negative effects of abiotic stress conditions related to climate adversities, combined with low fertility and organic matter soils, common in tropical conditions, such as the Nova Alta Paulista region, has led to the development of products that act on the physiological management of plants, enhancing water and nutrient uptake, in order to promote greater tolerance and plant growth under adverse conditions. The biostimulants used in agriculture are composed of organomineral substances and/or microorganisms aimed at increasing plant growth and development, and they may be a viable option to mitigate the negative effects of water and thermal stress in soybean crops. The adoption of technologies and products with biostimulant, biopromoter, or stress-attenuating effects is promising, especially due to their potential to promote root and shoot growth, which could provide significant benefits to soybean cultivation. The objective of the present proposal is to evaluate the effect of different forms and timing of application of a biostimulant based on amino acids and humic substances on the physiology (gas exchange parameters and LCI), nutrition (N accumulation in the shoot, root, straw, and soybean grains), growth, development (main biometric and productive components), and yield of soybeans. The research project will be conducted under field conditions in the municipality of Dracena - SP, in a typical sandy-textured Ultisol. The experiment will be conducted in a randomized block design with four replications, consisting of six treatments: 1) control - no biostimulant application; 2) 200 mL ha-1 of a biostimulant product based on amino acids and humic substances applied to the seeds + 300 mL ha-1 sprayed via foliar application at V4 (3 fully developed trifoliate leaves) + 300 mL ha-1 via foliar application at R1 (beginning of flowering); 3) 800 mL ha-1 at V2 (1 fully developed trifoliate leaf); 4) 800 mL ha-1 at V4; 5) 400 mL ha-1 at V4 + 400 mL ha-1 at R1; 6) 800 mL ha-1 at R1. The following will be evaluated: leaf chlorophyll index (LCI), gas exchange parameters (IRGA), dry mass and nitrogen (N) accumulation in shoots and roots at full soybean flowering (R2), dry straw mass, production components, grain yield at the end of the cycle (R8), as well as N accumulation in the straw and grains.