info:oai:icrisat:493info:ofi/fmt:xml:xsd:book92906640031999Efficient soil water use: the key to sustainable crop production in the dry areas of West Asia, and North and Sub-Shararan Africa: proceedings of the Workshop, Niamey, Niger, 26-30 April 1998 and proceedings of the Workhop, Amman, Jordon, 9-13 May 1999book