Suelos volcánicos de Nicaragua, 2: Contenido y distribución de azufre

Abstract

The studied soils are derived from volcanic materials and belong to the Pacific Region of Nicaragua. They have high temperatures (22–37°C) and annual rainfall fluctuations between 900 and 1,900 mm, belonging to the very dry and dry tropical forest formations according to the Holdridge system.

Total S values ​​(4964 and 1,3249 ppm) have been considered rather low for an area influenced by volcanic materials. The organic S percentage varies from 7.95 to 31.41, which means a low level. Nevertheless, this is the most important fraction because soil reserve S and exchangeable S depend on it. Inorganic S oscillates between 48.5 and 92.05 percent. Exchangeable S concentration is low, and calcium phosphate solution is considered the best extractor for these soils. Soil reserve S has an average value of 22.18 percent

The highest concentration of Organic-S is found near volcanoes, and it is located at 10 cm depth. Soil reserve-S and exchangeable SOS extracted with PO, H.K. show similar behavior, with respect to distance from the volcanoes and depth profile.