TEXTURE AND CHEMICAL-COMPOSITION OF SOILS FROM SHRIMP PONDS NEAR CHOLUTECA, HONDURAS

Analyses of bottom soils from three recently-established (newer) and t hree order ponds on each of two, semi-intensive shrimp farms near Chol uteca, Honduras, revealed that the 0 to 2.5 cm layer had greater conce ntrations of most variables than deeper layers. Concentrations of tota l carbon, nitrogen, sulphur, phosphorus, calcium, iron, manganese, and zinc were greater in older than in newer ponds on one or the other of the farms. After 8-11 y of continuous production, total carbon concen trations varied over pond bottoms, and concentrations usually were gre atest (1.5-2.5%) in intersections. Nitrogen concentrations were about 20% those of carbon and changes in nitrogen concentration closely foll owed those of carbon. Precipitation of iron pyrite (FeS2) in anaerobic soil layers was the apparent cause of sulphur accumulation in older p onds. Phosphorus accumulated in older ponds on the farm where heavy do ses of fertilizer were applied. Soils of both older and newer ponds on both farms had large accumulations of major cations, a large portion of which were water-soluble salts. There was no evidence of developmen t of adverse soil quality in older ponds.