Soil testing as a guide to fertilization in West Asia and North African (WANA) region

Abstract

This paper discusses and summarizes the potentials and problems of soil testing as a guide to fertilization in WANA region. The discussions separate the problems into three groups, which are associated with each of the three stages of any proper soil testing program. First, selection of appropriate soil tests: the diversity and incoherence of methods used in the region for determination of available N and P in soils are discussed; second, proper correlation of soil test values with crop responses (in this context the role and accomplishments of the “Regional Network on Soil Test Calibration,”; initiated by ICARDA in 1986, in field of selection, standardizing soil tests and soil test calibration are discussed; and third, development of fertilizer recommendations (the present system of fertilizer recommendation in the region is explained and the need for developing is more targeted fertilizer recommendations based on soil testing examined).