The cerrados of Brazil are typical of low-latitude tropical savannah areas in which agriculture is limited by low soil fertility and pH and high concentrations of aluminium. Since the 1960s, the traditional extensive cattle ranching has shifted to agriculture with the cultivation of rain-fed rice and, more recently, soybean [Glycine max (L.) Menill]. Introduction of soybean into these areas has depended on selection of cultivars carrying strategic genes determining a few key characteristics, principally late maturity, high aluminium tolerance and calcium-use efficiency. The methods used in developing adapted varieties are reviewed. Identification of the long-juvenile character and selection of genotypes in which this stage is prolonged are identified as keys in the systematic exploitation of plant yield potential. New screening techniques reveal that these savannah-adapted genotypes also carry genes for high-Al and low-Ca tolerances, which allow deep rooting of plants and, consequently, drought tolerance. The conjugation of these favourable characters is essential to the development of sustainable agriculture in the cerrados.
