Dynamics of carbohydrate partitioning and nutrient absorption in the split-root system of coffee plants in the interaction between Phosphorus, Potassium, and Magnesium

• Grant number: 24/19801-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2025
• End date: December 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Tiago Tezotto
• Grantee: Vinycius Leite da Silva Barbosa Resplandes
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 22/11773-0 - Phosphorus, potassium and magnesium in coffee and soybean plants: a physiological and molecular approach to the interaction of nutrients, AP.R

Abstract

Macronutrients potassium (K), magnesium (Mg), and phosphorus (P) are essential for plant development; however, their interactions can result in antagonism, as observed between K and Mg, or synergism, as seen between Mg and P. In Brazil, many crops, particularly coffee, face challenges related to nutritional management due to these soil interactions. The unbalanced application of nutrients can consequently compromise plant growth. In light of this context, the present project aims to investigate how these interactions influence coffee growth, focusing on nutrient absorption and carbohydrate partitioning. The research will be conducted under controlled conditions, using the split-root technique, where different nutrient concentrations will be applied to separate compartments of the root system. The compositions of the solutions that induce nutrient deficiencies have already been determined in previous stages of the thematic project. Three main treatments will be established: control, magnesium deficiency induced by excess potassium, and phosphorus deficiency caused by low magnesium levels, totaling 24 experimental units with 8 repetitions per treatment. Parameters such as root and shoot growth, CO¿ assimilation, and carbohydrate distribution will be evaluated. Additionally, the kinetic analysis of phosphorus and magnesium absorption will determine their rates under deficiency conditions. Physiological responses, such as chlorophyll index and dry biomass production, will also be monitored. Thus, this study aims to elucidate the mechanisms of interactions among these macronutrients, providing valuable information for more efficient nutritional management practices in coffee cultivation.