Phosphorus, Potassium and Magnesium in coffee plants-synergism and antagonism of nutrients

• Grant number: 23/08177-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2023
• End date: August 31, 2024
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Tiago Tezotto
• Grantee: Georgis Grigorios Augusto Kalintzis
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Potassium (K), magnesium (Mg) and phosphorus (P) play key roles in plant growth and development as they participate in physiological and biochemical processes, such as photosynthesis and protein synthesis. However, these nutrients interact with each other synergistically (Mg and P) and antagonistically (K and Mg), since K+ at high concentrations blocks the non-selective channels of Mg2+, decreasing the absorption of this element, which is necessary for the absorption of P. This way, these interactions may impact crop development if the nutrients balance in soil and fertilizations are not considered. In this context, the project seeks to identify the equilibrium relations between K, Mg and P in nutrient solution to maximize the root and shoot development of coffee. Coffee plants will be conducted in nutrient solution in a greenhouse of the Department of Soil Science (ESALQ/USP) at equilibrium ratios for K:Mg:P until they manifest symptoms of deficiency of Mg and P. From treatment 2 to 4 the ratios for K:Mg:P will be defined by the induction of P deficiency by the lower availability of Mg, while from treatment 5 to 8, this relation will be defined so that there is a competition between K and Mg that impacts on P deficiency. Each treatment will consist of 5 repetitions, totalizing 40 experimental units. At the end of the test, it will be calculated the kinetic parameters of phosphorus absorption, evaluated root growth (length, area and volume) and shoot, green index, dry matter mass in root, stem and leaves, and quantify the total nutrient contents in coffee due to the different nutrient balances in the nutrient solution. Thus, it is expected that the data obtained at the end of this research will serve as a starting point for other researches in the area of soil fertility and fertilizers and fertilization, besides favoring the understanding of an ideal balance between these nutrients, so that one does not compromises the absorption of the other and they promote the maximum development of this crop.