Gypsum and lime applications improve soil fertility under coconut cultivation in Eastern Amazon, Brazil

Abstract

ABSTRACT Gypsum and lime application causes chemical modifications in the soil that influence nutrient content, root growth and development of plants. An experiment was carried out in the municipality of Santa Isabel, Pará state, Brazil, to evaluate the chemical changes in the soil and the responses of green dwarf coconut to gypsum and lime at 6 and 12 months after application. The experimental design was completely randomized blocks, with 4 blocks and 7 treatments: T1 = control; T2 = 2000 kg ha-1 lime; T3 = 500 kg ha-1 gypsum; T4 = 2000 kg ha-1 lime + 300 kg ha-1 gypsum; T5 = 2000 kg ha-1 lime + 500 kg ha-1 gypsum; T6 = 2000 kg ha-1 lime + 700 kg ha-1 gypsum; T7 = 2000 kg ha-1 lime and 1000 kg ha-1 gypsum. After 12 months of applying the treatments, the combination of gypsum and limestone was used to reduce aluminum saturation, with values of 0% at a depth of 0.0-10 cm of the soil, as well as increments in sulfur contents and base saturation of the soil, with values of 70% at a depth of 0.0-10 cm of the soil; with positive effects on macronutrients concentrations in leaf tissue and on root growth. Application of agricultural gypsum, associated with lime, is efficient to improve the chemical attributes of the soil and the development of green dwarf coconut plants.