REDUCTION OF FERTILIZATION IN SOYBEAN GROWING IN SOIL WITH ACIDITY ALLEVIATED AND THE EFFECTS ON SORGHUM GROWING IN SUCCESSION

• Grant number: 23/12843-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): December 01, 2023
• Effective date (End): November 30, 2024
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Juliano Carlos Calonego
• Grantee: Giovani Munuera Robis
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The use of soluble mineral fertilizers in agricultural crops and dependence on imported sources has been the subject of debate due to the risk of shortages and price fluctuations, given international conflicts and exchange rate vulnerability. This scenario puts at risk the productive and economic sustainability of agricultural crops, especially grain crops with an annual cycle. It is a consensus that the alleviation of soil acidity is essential to increase the efficiency of the use of nutrients stored in the soil and/or coming from fertilizers. The objective of this work is to study, in soil subjected or not to correction of acidity with limestone, the effect of reducing the dose of fertilizer with P and K used in the soybean crop, grown in the summer season, evaluating the consequences on the yield of the crop itself (soybeans), as well as the residual effect on the yield of sorghum grown in succession, as autumn-winter crop, in No-Tillage System. In addition, the work will also aim to evaluate whether the differentiated fertilization of soybeans, whether in soil with alleviated acidity or not, will impact the response of sorghum to nitrogen fertilization. The experiment will be carried out in the 2023/2024 agricultural year, in Botucatu, SP, in continuation of an experiment started in the 2022/2023 harvest, in a Rhodic Ferralsol. The experimental design will be in randomized blocks, in a 3 x 2 x 2 factorial scheme, with four replications. The treatments will consist of three levels of mineral fertilization with PK in soybean growth (0, ½ and 1 times the recommended dose), without and with soil correction with dolomitic limestone, without and with nitrogen fertilization in sorghum. Evaluations will be carried out on foliar diagnosis, root production, nutrient cycling through the straw, crop yield parameters and protein content in the grains. Root production by crops and soil fertility will be evaluated along the soil profile. Data will be submitted to analysis of variance by F test and means compared by t LSD test (p d 0.05).