As and Se in soils and plants from abandoned mining areas of the Salamanca province, Spain.

In: Rodriguez-Barrueco (ed.): Fertilizers and Environment. Developments in Plant and Soil Sciences Volume 66. Kluwer Academic Publishers (Netherlands). (Proceeding of the International Symposium. "Fertilizers and Environment" held in Salamanca, Spain, 26-29, September, 1994).

Four mining zones were chosen for this study. The Morille, Montejo and Saucelle mining zones which produce tin and tungsten ores with sulphides hosted in shales. The Cabaco mining zone which produces tungsten ore with pyrite and arsenopyrite hosted in granites. In the Salamanca province, the arsenic background is less than 10 ppm in soils formed from granite and shales. Anomalous soils contain more than 10 ppm and range from 10 to > 1000 ppm, due to arsenopyrite alteration in mining areas. High and very high arsenic content in plants (9940669 ppb, some of them probably phytotoxic) were collected in these mining zones. The arsenic content in Vulpia bromoides (L) SF Gray, show a correlation with the arsenic content in the soils; nevertheless for Agrostis castellana Bois & Rent, other pedological factors (such as pH) must have a greater effect than the arsenic content in the soil. Dactylis glomerata L. has a higher degree of arsenic accumulation than Ag. castellana and Cynosurus echinatus L. in the same As-anomalous soil. On the other hand, the selenium contents in plants are low, with most of the data showing values lower than 50 ppb (which is considered to be deficient for animal nutrition) and ranging from 2 to 260. These values are in agreement with other data obtained previously in the Salamanca province. G: bromoides contain higher selenium levels than Ag. castellana in most of the soils studied.

Peer reviewed