PÓ DE ROCHA DE NEFELINA - SIENITO COMO FONTE POTÁSSICA: EFEITOS NA SOJA E NOS ATRIBUTOS QUÍMICOS DO SOLO

Abstract

Despite the magnitude of brazilian agribusiness, it is dependent on external inputs, especially potassium, which 96% of the total consumed comes from other countries. This situation has high production costs, leading to the need of using alternative fertilizers. In Brazil there are several types of rocks that can be used for this purpose, but they are little explored. The objective of this work was to evaluate biometric, physiological and productive aspects of soybean, testing Nepheline-Syenite (11.0% K2O) and KCl (58.0% K2O) and six doses of K2O (0, 25, 50, 100, 200 and 400 kg ha-1) as potassium sources. The work was carried out in the 2021/2022 harvest at Bonança Farm, Montes Claros de Goiás-GO, in a randomized block design, with four replications. In the R1 plants stage, chlorophyll content in the leaves, stem diameter, plant height, and dry mass of the aerial part were determined. At the time of harvest, the plant stand, grain moisture, weight of a thousand grain and productivity were determined. Regardless of the potassium source used, soybeans responded up to 100 kg ha-1 of K2O. The use of NephelineSyenite rock powder provided lower grain moisture at harvest. For the other variables, its application provided similar results to KCl, showing that its use as a K+ in soybeans is promising.