Affiliation: | (1) Instituto de Ecolog?a y Sistem?tica, IES, CITMA, Havana, Cuba;(2) Semiarid Prairie Agricultural Research Centre, AAFC, PO Box 1030, Swift Current, SK, S9H 3X2, Canada;(3) Department of Biofertilizer and Plant Nutrition, Instituto Nacional de Ciencias Agr?colas, San Jos? de las Lajas, La Habana, Cuba; |