<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">J Alegre</style></author><author><style face="normal" font="default" size="100%">Meza, A.A.</style></author><author><style face="normal" font="default" size="100%">Arévalo, L.A.</style></author></authors><secondary-authors><author><style face="normal" font="default" size="100%">asb@cgiar.org</style></author></secondary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Establecimiento De Barbechos Con Leguminosas.</style></title><secondary-title><style face="normal" font="default" size="100%">Agroforestería en las Américas </style></secondary-title><translated-title><style face="normal" font="default" size="100%">Establishment of fallow with legumes.</style></translated-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">acid soils</style></keyword><keyword><style  face="normal" font="default" size="100%">fallow</style></keyword><keyword><style  face="normal" font="default" size="100%">Legumes</style></keyword><keyword><style  face="normal" font="default" size="100%">slash and burn</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil fertility</style></keyword><keyword><style  face="normal" font="default" size="100%">tropics</style></keyword><keyword><style  face="normal" font="default" size="100%">vegetation</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://web.catie.ac.cr/informacion/RAFA/rev27/comoh1-a.htm</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">27</style></volume><pages><style face="normal" font="default" size="100%">31-33</style></pages><language><style face="normal" font="default" size="100%">Portuguese</style></language><abstract><style face="normal" font="default" size="100%">In many tropical areas is common to find acid soils with high aluminum saturation (toxic to many crops) and low concentrations of essential nutrients (mainly N, P, K, Ca and Mg), hampering the development of trees and crops. Traditional agriculture in many tropical areas has been based on slash and burn the forest, which quickly releases nutrients accumulated in the biomass of vegetation, allowing agriculture for a year or two.</style></abstract></record></records></xml>