T. S. Cuesta

The efficiency of different estimation methods of hydro-physical limits

The soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study area, measurement uncertainty, cost, effort and labour invested. In this paper, the efficiency of different methods for determining hydro-physical limits is evaluated by using indices that allow for the calculation of efficiency in terms of effort and cost. The analysis evaluates both direct determination methods (pressure plate - PP and water activity meter - WAM) and indirect estimation methods (pedotransfer functions - PTFs). The PTFs must be validated for the area of interest before use, but the time and cost associated with this validation are not included in the cost of analysis. Compared to the other methods, the combined use of PP and WAM to determine hydro-physical limits differs significantly in time and cost required and quality of information. For direct methods, increasing sample size significantly reduces cost and time. This paper assesses the effectiveness of combining a general analysis based on efficiency indices and more specific analyses based on the different influencing factors, which were considered separately so as not to mask potential benefits or drawbacks that are not evidenced in efficiency estimation.

Gestión de Aguas Residuales en el Ámbito Rural en Galicia, España

Este trabajo analiza la gestion de las aguas residuales procedentes de explotaciones agroganaderas mediante una encuesta a 4384 agricultores de Galicia, Espana. La Directiva Marco del Agua de la Union Europea destaca la consideracion del abastecimiento y saneamiento en las explotaciones agroganaderas. En el estudio se ha determinado la actitud y aptitud de los agricultores sobre la gestion del agua, con resultados variables en funcion del nivel de renta generado en la explotacion. Se muestra que las explotaciones mas competitivas son las que mayor disponibilidad muestran para adaptarse al nuevo marco legislativo.