Technologies for sustainable agriculture in the tropics :  proceedings of two international symposia sponsored by Division A-6 of the American Society of Agronomy in San Antonio, TX, and Denver, CO, 1990 and 1991 respectively / 
editors, John Ragland and Rattan Lal. 
 - Madison, Wis., USA :  American Society of Agronomy,  1993. 
 - xix, 313 p. :  ill.  
 - ASA special publication ;  no. 56 .
<br/><br/><label>ISBN: </label>0891181180 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sustainable agriculture--Tropics.<br/>Sustainable agriculture--Developing countries