Determination of soil fertility through a geographic information system in the Falcon municipality of the Paraguana Peninsula, Venezuela

Abstract

The objective of this work was to determine a chemical fertility index (CFI) in the soils of the Falcon municipality in the Paraguana Peninsula, based on the implementation of a geographic information system (GIS). A systematic soil sampling was carried out, collecting 395 samples at a depth of 0-20 cm. Maps were generated for each of the fertility-related properties, as well as the final CFI map at 1: 50,000 scale. The reserves (Kg/ha) of Potassium (K) were high in the soils of the entire municipality. For available Phosphorus (Pd) the highest values were found in the area of greatest agricultural influence. Available Nitrogen (Nd) is low throughout the area, except for some very small patches associated with specific microclimates that generate accumulation of organic matter. Soils have different pH levels; 50% of the surface has neutral soils (pH 6.5-7.5) and the other 50 %, alkaline soils (pH>7.5). The IFQ reflected that 60 % of the surface (1050 Km2) has low chemical fertility; and 40 % of the surface (712 Km2) soils ranging from medium to high fertility. Despite the fact that a large area of soils in the Falcón municipality has a high potential fertility, it is important to consider the low availability of water, both in quantity and quality in arid zones, which implies that the main limitation for agricultural production would be given due to the low availability of water in the area.