Land Evaluation in a Salt-Affected Irrigated District Using an Index of Productive Potential

/ The indiscriminate allocation of funds supporting agricultural policies can lead to land misuse, with undesirable effects either on the shorter to mid-term productivity or on the environment. This article proposes a methodology, based on land rating, that can be useful to land-use planning or to decide about environmental protection measures. The methodology is applied to the land evaluation of a 260-km(2) semiarid irrigated area with salt-affected soils. The available soil map is at 1:100,000 scale and its mapping units are used for the land evaluation with the FAO framework. These data are then elaborated using the index value method. This procedure gives a map of land evaluation units and a table that rates the productive potential of these units for six crops: alfalfa, barley, maize, rice, sunflower, and wheat.