Methodology for edaphoclimatic assessment of olive cultivation: Application to the area of the quality mark “Olive Oil Madrid” (Spain)OLIVE OIL MADRID” (SPAIN)

The present work proposes a methodology to select the most suitable areas for olive cultivation under rainfed conditions in the Madrid Region (Central Spain). This methodology is based on an analysis of the significant edaphoclimatic parameters that characterize the study region matched with the crop requirements of the olive tree, in the framework of the Land Suitability Classification system. A key component of the proposed methodology is the selection and rating of edaphic and climatic parameters as limitations associated with olive crop requirements in rainfed conditions. The climatic parameters considered are: average temperature of the absolute minimum of the coldest month (during dormancy and growth periods), average temperature of the minimum in the phenological stages of flowering, growth and ripening, mean relative humidity in spring and autumn, and average annual sunshine hours. The edaphic parameters considered (both extrinsic and intrinsic to soil profiles) include: slope, stoniness and rockiness, drainage, presence of perched water table, infiltration rate, effective depth, available water retention capacity (AWC), cation exchange capacity (CEC), pH, base saturation, active lime, salinity, Ca/K antagonism and organic matter content. For each of these parameters, five levels of severity have been established, from "very unfavorable" (excluded) to "very favorable" (optimal), establishing specific limits within each of these ranges to compare them with the requirements of olive trees. The final phase of the evaluation is the allocation of Suitability Categories to certain areas of interest for olive growing, established according to soil and climate criteria, on the basis of Land Mapping Units defined on the studied territory. The interest of an edaphoclimatic assessment in this geographical area lies in its marginal location with respect to the main olive groves in the Iberian Peninsula, and in the variety of existing climatic and edaphic conditions, some of them generally considered as limiting the cultivation of the olive grove, as well as in an evident current expansion of this crop. The most relevant edaphic limitations derive especially from a low available water capacity, and locally, by factors such as acid pH, Ca/K antagonism or high active lime. The exclusionary limitations derive, to a great extent, from climatic characteristics, associated with low temperatures combined with high relative air humidity. This methodology is expected to serve as a basis for the delimitation of new areas on which the implantation of the olive grove may be foreseen within a period, like the present one, of remarkable expansion of this crop.