Indicadores de qualidade do solo sob cultivo do cafeeiro em função de doses de adubo mineral e organomineral.

Abstract

Organomineral fertilizers have been widely used in coffee growing, providing nutrients, increasing organic matter in the soil and encouraging the loss of essential elements to plants. In this context, a survey was carried out with the aim of evaluating soil quality indication parameters under coffee cultivation as a function of mineral and organomineral fertilizer doses, using native forest soil as a reference. The experiment was installed at Araras 2 Farm, located in Monte Carmelo, Minas Gerais. The crop was planted in December 2016, using seedlings of the cultivar MGS Paraíso 2, spacing 3.8 m between rows and 0.6 m between plants. The experimental design used was in randomized blocks with five blocks and six treatments: (T1) 100% of the treatment with organomineral, (T2) 70% of the treatment with organomineral, (T3) 50% of the treatment with organomineral, (T4) 100% of mineral fertilization, (T5) standard treatment of the property and (T6) 70% of mineral fertilization. In addition, a treatment corresponding to the native forest (T7) was inserted. The evaluations of the parameters electrical conductivity, pH (in CaCl2 and deionized water), basal respiration of the soil, assimilable phosphorus and organic matter were carried out in September 2020 and September 2022. In the two years evaluated, there was an increase in pH in water and calcium chloride in fertilized soils compared to native forest. The electrical conductivity of soils using mineral or organomineral fertilizer showed an increase of 101.08 and 128.69 µs cm-1 in relation to native forest, respectively in the years 2020 and 2022. For soil basal respiration, organic matter and available phosphorus content, there were no differences between fertilizer sources in relation to native forest in the year 2020. In 2022, a higher basal respiration rate (TRB) was detected in the soil corresponding to the producer's pattern. In treatments with doses of organomineral fertilizer, there was an average increase of 0.67 mg C-CO2/kg.h in the TRB in relation to native forest soil. The highest organic matter content, in 2022, was observed in native forest soil in relation to fertilized treatments.