Soils and agriculture in central-west and north Brazil

Modern soil science, spearheaded by research in Brazil has facilitated the utilization of vast areas of previously uncultivated soil long considered unsuitable for human food production into highly productive agricultural land. Naturally acid soils with high contents of aluminum and iron oxides and low CEC values and organic matter contents long considered insurmountable obstacles to crop production in tropical latitudes could be extremely productive. With continued development of the infrastructure needed by commercial agriculture Brazil has the potential to lead the world in its quest to provide food for growing human populations.A moderna ciência de solo, liderada pelas suas pesquisas no Brasil, tem possibilitado a utilização de vastas áreas de solos, durante muito tempo não cultivados por serem avaliados como inaptos para uma intensiva produção de alimentos. Hoje, ao contrário, constata-se que essas terras são altamente produtivas para a agricultura. Estas pesquisas vêm mostrando que alguns atributos naturais destes solos, como acidez, baixos teores de matéria orgânica, baixa capacidade de troca de cátions, além de altos teores de óxidos de ferro e/ou de alumínio - considerados como obstáculos à produção de boas colheitas em latitudes tropicais - podem ser superados. Com a continuação do desenvolvimento das infra-estruturas necessárias para alavancar ainda mais a agricultura comercial, o Brasil tem potencial para, em breve, liderar o mundo no que tange ao fornecimento de alimentos para as crescentes populações humanas

Copper chloride as an extractant for estimating the potentially reactive aluminum pool in acid soils

The reactive Al pool in selected Ultisols, Oxisols, and Histosols from Africa, South America, and North Carolina was estimated by extraction with 1N CuCl2. The Al-saturated clay minerals with and without interlayered hydroxy-Al were used to compare the extractability of Al by 1N CuCl2 and 1N KCl. The 1N solutions of KCl and CuCl2 were equally effective in extracting exchangeable Al from an Al saturated montmorillonite. The 1N CuCl2 solution, however, extracted almost twice as much Al from an Al saturated vermiculite containing a hydroxy Al interlayer as compared with 1N KCl. Generally, more than twice as much Al was extracted from acid surface soils (< pH 5) by 1N CuCl2 than by 1N KCl suggesting that Al bound by organic matter was being extracted by the CuCl2