ABSTRACT
RESUMO O objetivo principal do presente trabalho foi diagnosticar a situação da área em estudo, incluindo o corpo hídrico que é abastecido pelo Córrego Samambaia. Foram realizadas medições de altura e diâmetro das espécies arbóreas, durante 12 meses. Além disso, ocorreram coletas de amostras da água da represa para análise dos parâmetros: pH, condutividade, fósforo total e metais pesados. Nos meses de julho e dezembro de 2014, foram realizadas análises de turbidez, cor, demanda bioquímica de oxigênio (DBO) e oxigênio dissolvido (OD). Foram também realizadas análises físico-químicas do solo. No monitoramento realizado de setembro de 2013 a agosto de 2014, algumas plantas tiveram boa resposta em relação ao uso dos adubos verdes; porém, outras tiveram alta mortandade durante o estudo, como foi o caso do pequi. A competição entre espécies exóticas e nativas foi reduzida, o que aumentou, em geral, a sobrevivência das espécies nativas do bioma do Cerrado. Elementos tais como manganês não apresentaram diferença significativa em todos os tratamentos nos períodos de avaliação. Os valores de macro e microporos foram parecidos, mas a área apresentou diferenças quanto à textura do solo analisado. Quanto aos testes de resistência à penetração (RP) feitos em áreas com e sem adubo verde, os maiores valores foram encontrados na área sem as espécies leguminosas, onde o solo estava mais compactado. Parâmetros como condutividade elétrica da água apresentaram-se estáveis durante os 12 meses de estudo. Os resultados para OD e DBO estão fora do preconizado pela Resolução nº 357 do Conselho Nacional do Meio Ambiente.
ABSTRACT The main objective of this paper was to diagnose the situation of the study area, including the water body that is fueled by Córrego Samambaia. Measurements of height and diameter of tree species were made for 12 months. In addition, dam water samples were collected and the following parameters were analyzed: pH, conductivity, total phosphorus and heavy metals. In July and December of 2014, turbidity, color, biochemical oxygen demand (BOD) and dissolved oxygen (DO) analyzes were made. Physico-chemical analyses of soil were also carried out. Monitoring carried out from September 2013 to August 2014 showed some plants with good response in relation to the use of green manures, but others showed high mortality during the study, as the pequi. The competition between alien and native was reduced, which increased overall survival. Elements such as manganese showed no significant difference in all treatments during evaluation's period. Macro and micropores values were similar, but for texture, the area showed some differences. For penetration resistance tests (PR) made in an area with and without green manure, the largest PR values were found in the one without legumes species. Parameters such as electric conductivity were stable during the 12 months of study. The results for DO and BOD are outside the recommended by the Resolution 357 of the National Environmental Council.
ABSTRACT
Abstract This study aimed to evaluate the tolerance to salinity and temperature, the genetic diversity and the symbiotic efficiency of rhizobia isolates obtained from wild genotypes of common bean cultivated in soil samples from the States of Goiás, Minas Gerais and Paraná. The isolates were subjected to different NaCl concentrations (0%, 1%, 2%, 4% and 6%) at different temperatures (28 °C, 33 °C, 38 °C, 43 °C and 48 °C). Genotypic characterization was performed based on BOX-PCR, REP-PCR markers and 16S rRNA sequencing. An evaluation of symbiotic efficiency was carried out under greenhouse conditions in autoclaved Leonard jars. Among 98 isolates about 45% of them and Rhizobium freirei PRF81 showed a high tolerance to temperature, while 24 isolates and Rhizobium tropici CIAT899 were able to use all of the carbon sources studied. Clustering analysis based on the ability to use carbon sources and on the tolerance to salinity and temperature grouped 49 isolates, R. tropici CIAT899 and R. tropici H12 with a similarity level of 76%. Based on genotypic characterization, 65% of the isolates showed an approximately 66% similarity with R. tropici CIAT899 and R. tropici H12. About 20% of the isolates showed symbiotic efficiency similar to or better than the best Rhizobium reference strain (R. tropici CIAT899). Phylogenetic analysis of the 16S rRNA revealed that two efficient isolates (ALSG5A1 and JPrG6A8) belong to the group of strains used as commercial inoculant for common bean in Brazil and must be assayed in field experiments.