Avaliação do pH e da matéria inorgânica no solo do mangal da área de reflorestamento do Icídua no estuário dos Bons Sinais-Quelimane

Abstract

Mangrove is a coastal ecosystem, found in tropical and subtropical regions, serving as a barrier for some coastal communities protecting them from erosion, cyclones and other natural phenomena. Mangrove plants depend on pH, inorganic nutrients and other parameters contained in the soil for their growth and development. The present study was carried out in the district of Icídua in the district of Quelimane to investigate pH and inorganic matter in the mangrove soil of the reforestation area in the Bons Sinais estuary. It was carried out in two exits: 1st exit: May 15, 2016 and 2nd exit: October 09, 2016, all in the living tide. The soil was collected at a depth of 50 cm using a soil titer. The method for obtaining water samples consisted of weighing 10 grams of soil and dissolving in 100 ml of distilled water. The pH was determined by a PH-meter of the HANNA HI83141 brand field and the inorganic matter was determined by a portable photometer (MultiDirect_7). After the determinations of pH and inorganic matter, the dilution factor was considered. The pH had a maximum value of 6 ± 0 in the proximal, intermediate and distal zones "A", the values decreased with the bottom and with the exception of the zone "B" that remained. Ammonia concentrations were highest in the "B" distant zone with 413 ± 274 mg/L, in the distant zone "B" decreased along the depth. The nitrate had a maximum concentration of 1160 ± 379 mg/L in the distant zone "A", in the intermediate zone the concentrations increased with the sedimentary bottom. The highest phosphate concentration of 157 ± 135 mg/L was found in the intermediate zone, the concentrations decreased with the depth in the intermediate zone and distant zone "A". And the highest silicate concentration was 137 ± 9 mg/L in the distant zone "A", and in the soil depth the concentrations in the proximal zone and the "B" zone increased from the surface to the bottom. The study concluded that pH values and inorganic nutrient concentrations were adequate for mangrove growth and development.