Small-scale and household low-cost technologies to provide water free of arsenic for drinking purposes, suitable for isolated rural and periurban areas not connected to water networks in Latin America are described. Some of them are merely adaptation of conventional technologies already used at large and medium scale, but others are environmentally friendly emerging procedures that use local materials and resources of the affected zone. The technologies require simple and low-cost equipment that can be easily handled and maintained by the local population. The methods are based on the following processes: combination of coagulation/flocculation with adsorption, adsorption with geological and other low-cost natural materials, electrochemical technologies, biological methods including phytoremediation, use of zerovalent iron and photochemical processes. Examples of relevant research studies and developments in the region are given. In some cases, processes have been tested only at the laboratory level and there is not enough information about the costs. However, it is considered that the presented technologies constitute potential alternatives for arsenic removal in isolated rural and periurban localities of Latin America. Generation, handling and adequate disposal of residues should be taken into account in all cases.

RESUMO -O sistema plantio direto é uma estratégia sustentável de produção que preconiza a manutenção da cobertura vegetal como prática conservacionista do solo. Objetivou-se avaliar o efeito de plantas de cobertura sobre atributos fisiológicos e agronômicos do milho na região sudoeste da Amazônia. Foram avaliadas 15 estratégias de sucessões de culturas com o milho e a influência sobre o rendimento de biomassa, de grãos, altura de plantas e inserção da espiga, índice de espiga, massa de 100 grãos, teor foliar de nitrogênio e clorofilas total, a e b em plantas de milho.Observou-se efeito das plantas de cobertura sobre o rendimento de grãos, de biomassa fresca e seca, na massa de grãos e nos teores de clorofila. Os efeitos sobre os teores de clorofila foram mais pronunciados na clorofila b e nos estádios fenológicos finais da cultura. O feijão-de-porco promoveu as maiores produtividades de grãos (7.539,3 kg ha -1 ) e potencial de silagem (16,2 Mg ha -1 de biomassa seca). A adequada escolha das espécies que compõe um sistema de plantio direto é preponderante para o apropriado desempenho agronômico do milho na região sudoeste da Amazônia. Palavras-chave:Zea mays, intensificação ecológica, sustentabilidade, integração lavoura-pecuária, plantio direto. CROPPING SYSTEMS ON THE PERFORMANCE OF CORN PLANTS IN THE SOUTHWESTERN AMAZONABSTRACT-A sustainable strategy for agricultural systems is the use of cover crops in no-tillage systems, as a conservationist soil practice. This paper aimed to evaluate the short-term effects of different cover crops on some physiological and agronomic attributes of corn crop in the Southwestern Amazon region. The effects of 15 cover plants on the biomass and grains yield, plant height, ear insertion height, ear index, mass of 100 grains, leaf nitrogen content and a, b and total chlorophyll levels of corn plants were evaluated. A randomized complete block design was used with four replications. Grain yield, fresh and dry biomass yield, mass of 100 grains and chlorophyll content were affected by some cover crops. Jack bean promoted the highest grain yield (7,539.3 kg ha -1 ) and biomass yield (16.2 Mg ha -1 dry matter) among the options assessed. Cover crops provided different levels of total, a and b chlorophyll levels, on the corn plants. Some cover crops presented the potential to improve the agronomic performance of the succeeding corn crop in the Southwestern Amazon region. The proper agronomic performance of corn in a no-till system depends on the adequate choice of cover plants to compose the system. Sorgo, v.15, n.3, p. 531-542, 2016 RESUMO -O sistema plantio direto é uma estratégia sustentável de produção que preconiza a manutenção da cobertura vegetal como prática conservacionista do solo. Objetivou-se avaliar o efeito de plantas de cobertura sobre atributos fisiológicos e agronômicos do milho na região sudoeste da Amazônia. Foram avaliadas 15 estratégias de sucessões de culturas com o milho e a influência sobre o rendimento de biomassa, de grãos, altura de plantas e inserção da e...

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This study constructed a fi re risk map for the Serra de São Domingos Municipal Park (SSDMP), southern Minas Gerais Sate, Brazil, which harbors Atlantic Forest remnants and endangered species. Geo-processing techniques were used for producing a preliminary risk map for altimetry (a), land slope (e), slope orientation (d), land-use/cover (u) and infl uence of roads and buildings (i). After, the risk maps were overlaid to produce a structural fi re index (SFI)-based risk map for the Park. The SFI was calculated by using the formula SFI = 0,35i + 0,30u + 0,15d + 0,10a + 0,10e. The risks classes were classifi ed as low (0.0-0.9), moderate (1.0-1.9), high (2.0-2.9), very high (3.0-3.9) and extreme (4.0-5.0). All data were processed with 2.5 m base spatial resolution by using the ArcView GIS. According to the SFI calculated, the SSMP area can be divided into the following fi re risk zones: Low (0.93%), Moderate (61.77%), High (31.32%), Very High (4.79%) and Extreme (1.19%). The main risk factor is due to the infl uence of roads and buildings and most fi res start due to anthropogenic causes. The low and moderate risk classes comprehend most of the rainforest area. Clearings and grasslands fi t mainly the High risk class. The most vulnerable area of SSDMP was the Northern area bordering pasture, crops and eucalypt fi elds. The SFI map can be a valuable tool for elaborating a fi re prevention plan in a small conservation unit when few climate and fi re occurrence data are available.Key words: Atlantic Forest, conservation unit, fi re prevention, on-the-screen visual image interpretation. Baixo (0,9), Moderado (1,[0][1]9), Alto (2,[0][1][2]9), Muito Alto (3,[0][1][2][3]9) e Extremo (4,(0)(1)(2)(3)(4)(5)0 ZONEAMENTO DE RISCO DE INCÊNDIOS PARA O PARQUE MUNICIPAL DA SERRA DE SÃO DOMINGOS, POÇOS DE CALDAS, MG RESUMO: Objetivou-se, com este estudo, produzir um mapa de risco de incêndio para o Parque Municipal da Serra de São Domingos (PMSSD), sul de Minas Gerais, Brasil, que abriga remanescentes de Mata Atlântica e espécies ameaçadas de extinção. Técnicas de Geoprocessamento foram utilizadas para produzir mapas de risco preliminares para altimetria (a), declividade do terreno (e), uso e cobertura do solo (u), orientação de encosta (d) e infl uência de estradas e construções (i). Os mapas foram integrados, gerando um mapa baseado no índice estrutural de risco de incêndio (SFI) calculado pela fórmula SFI = 0,35i + 0,30u + 0,15d + 0,10 a + 0,10e. As classes de risco foram defi nidas como

SUMMARYAcacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As)-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg -1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg -1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg -1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used.Index terms: arsenate, heavy metals, phytoremediation, root anatomy, soil contamination.(