Evaluation of pea seed vigor by the accelerated aging and controlled deterioration tests

Vigor tests were developed to detect differences in seed lots due to limitations of germination tests. The objective of this work was to investigate the efficiency of the accelerated aging and controlled deterioration tests to assess the vigor of pea seed lots. The water content and physiological quality of five pea lots cv. Aragon were determined using the germination and vigor tests (first count, electrical conductivity, seedling emergence and speed of emergence index, accelerated aging with the traditional system and with saturated NaCl solution at 41ºC for 48, 72 and 96 hours; and controlled deterioration test with 15, 20, 25% water content for 48, 72 and 96 hours at 42ºC). The accelerated aging test with saturated NaCl solution for 96 hours was efficient to categorize pea seeds lots. Combinations of 20% water for 72 hours and 25% water for 48 and 72 hours were efficient to categorize pea seed lots using the controlled deterioration test

Vigor of lentil seeds evaluated by the tests of accelerated aging and controlled deterioration / Vigor de sementes de lentilha avaliadas pelos testes de envelhecimento acelerado e deterioração controlada

The objective of this work was to investigate the efficiency of the accelerated aging and controlled deterioration tests in the evaluation of lentil seeds’ vigor. Water content was determined and the physiological quality was evaluated using germination and vigor tests (first count, seedling emergence, indices of germination speed and emergence, accelerated aging test with traditional method and with NaCl saturated solution at 41ºC and 45ºC for 24, 48, 72 hours and controlled deterioration with 20% and 24% water content for 24, 48 and 72 hours at 45ºC) in seven lots of lentil seeds cv Silvina. The use of traditional accelerated aging test and the NaCl saturated solution method at 41ºC for 48 hours were efficient to classify lentil seeds’ lots. The combination of 20% and 24% water for 48 hours exposure and of 20% water for 72 hours exposure were efficient to classify the lentil seed lots by the controlled deterioration test. 

Desenvolvimento socioeconômico na região de Matopiba, Brasil / Socioeconomic development in the region of Matopiba, Brazil

A região de MATOPIBA, que compreende o bioma do Cerrado dos estados do Maranhão, Tocantins, Piauí e Bahia, é considerada a nova fronteira agrícola e tem se destacado como uma área de expansão e produtividade do agronegócio brasileiro. Este estudo analisa o desenvolvimento socioeconômico desta região, com base no Índice FIRJAM de Desenvolvimento Municipal (IFDM). Para isso, foi levantado o indicador em suas três dimensões – emprego e renda, educação e saúde ­– nos anos de 2005 e 2016, para todos os municípios que fazem parte de MATOPIBA. Em seguida os dados foram submetidos a testes estatísticos para comparar o desempenho dessa região nos dois anos estudados. Os resultados evidenciam que os municípios de MATOPIBA tiveram um crescimento significativo nas dimensões educação e saúde. 

Natural variation of arsenic fractions in soils of the Brazilian Amazon

Arsenic (As) in native soils of the Amazon rainforest is a concern due to its likely origin from the Andean rivers, which transport loads of sediments containing substantial amounts of trace elements coming from the cordilleras. Yet, unveiling soil As baseline concentrations in the Amazon basin is still a need because most studies in Brazil have been performed in areas with predominantly high concentrations and cannot express a real baseline value for the region. In this study, 414 soil samples (0–20, 20–40 and 40–60 cm layers) were collected from different sites throughout the Amazon basin - including native Amazon rainforest and minimally disturbed areas - and used to determine total and extractable (soluble + available) As concentrations along with relevant soil physicochemical properties. Descriptive statistics of the data was performed and Pearson correlation supported by a Principal Component Analysis (PCA) provided an improved understanding of where and how As concentrations are influenced by soil attributes. Total As concentration ranged from 0.98 to 41.71 mg kg−1 with values usually increasing from the topsoil (0–20 cm) to the deepest layer (40–60 cm) in all sites studied. Considering the proportional contribution given by each fraction (soluble and available) on extractable As concentration, it is noticeable that KH2PO4-extractable As represents the most important fraction, with >70% of the As extracted on average in all the sites studied. Still, the extractable fractions (soluble + available) correspond to ~0.24% of the total As, on average. Total, available, and soluble As fractions were strongly and positively correlated with soil Al3+. The PCA indicated that soil pH in combination with CEC might be the key factors controlling soil As concentrations and the occurrence of each arsenic fraction in the soil layers

A Correlação Da Obesidade Infantojuvenil Com A Diabetes Mellitus

RESUMO: A obesidade entre crianças e adolescentes é uma preocupação mundial de saúde pública. Assim, é evidente o aumento da incidência tanto de diabetes tipo 1 quanto do tipo 2, uma vez que fatores de risco como a obesidade juntamente com a hereditariedade e o status socioeconômico se fazem presentes. Diante do exposto, se faz necessária a investigação que demonstre a relação de como a prevalência de obesidade e sobrepeso é afetada por esse status, como também esse predomínio estabelece relação de causa consequência com a diabetes mellitus. Existe uma correlação positiva entre sobrepeso e obesidade com determinadas síndromes metabólicas, como dislipidemias e resistência à insulina, tornando-os mais suscetíveis ao diagnóstico de diabetes mellitus

Installation and calibration of sensors for analysis of soil humidity and temperature in eastern Amazon areas

Soil moisture and temperature are important components to improve watershed management and natural resource planning, especially in areas where water supplies are limited during dry seasons. Thus, this study aimed to evaluate the installation and calibration of five sensors (Drill & Drop) as well as the consistency of the results obtained for moisture and soil temperature in areas of forest, pasture, forest-pasture transition and pasture-urban transition in the Itacaiúnas River Hydrographic Area (BHRI) in the Eastern Amazon. The results refer to the period from April to September 2019, showing different trends between forest and pasture areas. The data consistency analysis efficiently identified measurement errors, especially in the surface layer of the soil (10 cm). The Onça Puma and IFPA Rural stations had the highest percentages of error data 22.8% and 17.6%, respectively. On the other hand, these results may be associated with the environmental characteristics of the region, as well as the physical characteristics of the soil during each season. The soil temperature and humidity parameters were consistent with data from other meteorological variables (precipitation and mean air temperature) measured by sensors installed in the local hydrometeorological stations. Overall, the soil moisture and temperature measurements were obtained properly and are presented as quality data sources. Thus, it is expected that the results will contribute to enriching the availability of soil data in the IRB and encouraging the use of direct measurements given the quantity (and quality) of data obtained using this instrumentation.Soil moisture and temperature are important components to improve watershed management and natural resource planning. In that way, this article aimed to evaluate the installation and calibration of five sensors (Drill & Drop) as well as the consistency of the results obtained for moisture and soil temperature in areas of forest, pasture, forest-pasture transition, and pasture-urban transition in the Itacaiúnas River Hydrographic Area (IRB) in the Eastern Amazon. The results are from April to September 2019, showing different trends between forest and pasture areas. The data consistency analysis efficiently identified measurement errors, especially in the soil’s surface layer (10 cm). The highest percentage of error data occurred in the Onça Puma and IFPA rural stations, with 22.8% and 17.6%. On the other hand, these results may be associated with the environmental characteristics of the region, as well as the soil’s physical characteristics during each season. The soil temperature and humidity parameters were consistent with data from other meteorological variables (precipitation and mean air temperature) measured by sensors installed in the local hydrometeorological stations. Generally, the temperature and soil moisture measurements were obtained properly and are presented as quality data sources. Thus, it is expected that the results will contribute to enriching the availability of soil data in the IRB and encourage the use of direct measurements given the quantity (and quality) of data obtained using this instrumentation

Natural variation of arsenic fractions in soils of the Brazilian Amazon

Arsenic (As) in native soils of the Amazon rainforest is a concern due to its likely origin from the Andean rivers, which transport loads of sediments containing substantial amounts of trace elements coming from the cordilleras. Yet, unveiling soil As baseline concentrations in the Amazon basin is still a need because most studies in Brazil have been performed in areas with predominantly high concentrations and cannot express a real baseline value for the region. In this study, 414 soil samples (0–20, 20–40 and 40–60 cm layers) were collected from different sites throughout the Amazon basin - including native Amazon rainforest and minimally disturbed areas - and used to determine total and extractable (soluble + available) As concentrations along with relevant soil physicochemical properties. Descriptive statistics of the data was performed and Pearson correlation supported by a Principal Component Analysis (PCA) provided an improved understanding of where and how As concentrations are influenced by soil attributes. Total As concentration ranged from 0.98 to 41.71 mg kg−1 with values usually increasing from the topsoil (0–20 cm) to the deepest layer (40–60 cm) in all sites studied. Considering the proportional contribution given by each fraction (soluble and available) on extractable As concentration, it is noticeable that KH2PO4-extractable As represents the most important fraction, with >70% of the As extracted on average in all the sites studied. Still, the extractable fractions (soluble + available) correspond to ~0.24% of the total As, on average. Total, available, and soluble As fractions were strongly and positively correlated with soil Al3+. The PCA indicated that soil pH in combination with CEC might be the key factors controlling soil As concentrations and the occurrence of each arsenic fraction in the soil layers

Assessing the most sensitive and reliable endpoints in plant growth tests to improve arsenic risk assessment

Arsenic (As) is toxic to humans and the environment. Its toxicity has been assessed in many ways, including plant growth tests integrated in As risk assessments (RA). The tiered approach used in RA schemes assumes that lower tiers are more conservative than higher tiers. Plant growth tests may comprise lower tier of a RA and include the measurement of several endpoints. However, only few of these endpoints are highly sensitive and reliable, which makes them more appropriate to comprise lower tiers. Therefore, the selection of those endpoints is needed. The present study aimed to evaluate the most appropriate endpoints of plant growth tests to use in lower tier As RA schemes. This selection of endpoints was based on their sensitivity and reliability, using different tropical soils and plant species. In order to achieve this objective, six plant species were exposed to eight levels of As contamination (0; 8; 14.5; 26; 46.5; 84; 150; 270 mg kg−1), in three different tropical soils (Oxisol, Inceptisol, and tropical artificial soil). The endpoints measured were: first germination count (FrC), plant height (PH), relative leaf area (RLA), stem diameter (SD), total germination (TG), germination speed index (GSI), dry mass (DM), number of completely expanded leaves (CEL), plant survival (PS), soil plant analysis development chlorophyll level (SPAD), and the final germination count (FnC). Toxic values for 50% of effect were estimated for each endpoint within each species and test soil, to rank them according to their sensitivity and reliability. The most sensitive endpoints were: FrC, RLA, DM, GSI, PH, and FnC, while the most reliable endpoints were: FrC, DM, GSI, DM, PH, FnC, and TG. Our findings suggest that FrC, DM, GSI, PH, and FnC are the most adequate endpoints to be used in plant growth tests as lower tiers of As RA in tropical regions

Assessing the Brazilian prevention value for soil arsenic: effects on emergence and growth of plant species relevant to tropical agroecosystems

One of the entry routes of arsenic (As) into the food chain is through the consumption of edible parts of crops contaminated by this element. Different plant species present distinctive As accumulation and tolerance capacities. These differences are also influenced by As availability and speciation in soils. This study assessed the effect of As contamination on plant emergence and initial growth, as well as on accumulated As contents in different crops grown in tropical soils. In addition, it was intended to verify the protection level of the current soil As prevention value adopted in Brazil, which should be applicable for conceivably other tropical soils in Latin America. Plants of maize, rice, sorghum, common bean, sunflower, and radish were cultivated in two different tropical soils (Oxisol and Inceptisol) and in a standard substrate (tropical artificial soil - TAS) dosed with As (0; 8; 14.5; 26; 46.5; 84; 150; 270 mg kg−1). Early germination, total dry mass, As content, and bioconcentration factor were evaluated. The EC20 and EC50 values (the As concentration for 20% or 50% of effect relative to control treatment) based on total As concentration were more variable among different soils than the corresponding EC20 and EC50 values based on extractable (phytoavailable) As concentration. From the studied species, common bean was the most sensitive and maize was the least sensitive to As. Those species were the ones that accumulated the lowest As levels in shoot tissues. Arsenic concentrations measured in plant tissues and estimated bioaccumulation factors were not related to relative As toxicity among species. Data obtained suggest that the current Brazilian prevention value for arsenic is adequate for soils with high arsenic adsorption capacity

Native Plant Species as an Alternative to Rehabilitate Iron Ore Waste Piles in Carajás Mineral Province, Brazil

The selection of promising and appropriate plant species and knowledge of their effects on the soil are essential for mineland rehabilitation success. The present study evaluated the effects of three different plant seed cocktails on fertility, soil cover, and erosion control in two iron waste piles in the Carajás Mineral Province, Eastern Amazon, Brazil. The three different seed cocktails were: commercial (only commercial species); native (only species native of Carajás); mixed (native and commercial species); and a control treatment (without seed application). Additionally, tillers from native grasses from Carajás were planted in one of the waste piles. The cocktails were applied by hydroseeding together with fertilizer, mulch, organic compost, and a tackifier. Analyses were performed at 12 and 24 months after the seeding in the waste piles. In general, all cocktails contributed to vegetation establishment, organic matter accumulation, and increased soil fertility. The commercial cocktail stands out due to its ability to improve soil fertility. Native species showed the best cover performance, and less soil loss, highlighting their use for effective control of soil erosion. Thus, native species have the potential for use in rehabilitation projects involving iron waste piles in the Amazon. This is especially relevant because the use of native plant species is mandatory and a declared rehabilitation target.</p