Potencial de terras para irrigação na Bacia do Tucano-BA.

O objetivo deste estudo foi avaliar o potencial de terras para irrigação numa área de aproximadamente 26.162 km2 na Bacia do Tucano, Estado da Bahia. A base das interpretações foi o levantamento de solos realizado pela Embrapa na escala de 1:1.000.000. A metodologia utilizada foi a do Bureau of Reclamation (BUREC) com simplificações. As terras consideradas irrigáveis foram enquadradas nas classes 2 e 3. As da classe 2 ocupam 641,39 km2, isto é, cerca de 2,46 % da área total. Nesta classe são encontrados principalmente Cambissolos e Vertissolos. As terras da classe 3 ocupam 9.180,97 km2, cerca de 35,08 % da área total. Estão representadas principalmente por Latossolos e Argissolos. A maior parte das terras são consideradas não irrigáveis (classe 6) e ocupam 16.339,91 km2, cerca de 62,46 % da área total

Estudos de Solos do Município de Aceguá, RS

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Alterações nas características químicas de um argissolo acinzentado decorrente da aplicação de compostos orgânicos.

Práticas de manejo do solo afetam as suas propriedades e como a fertilidade dos solos depende da quantidade e qualidade da sua matéria orgânica, é muito provável que mudanças causadas pelas práticas de manejo afetem diretamente a fertilidade dos mesmos. Este trabalho teve como objetivo avaliar as alterações nas propriedades químicas de um Argissolo Acinzentado em função da aplicação de compostos orgânicos em sistema orgânico de produção de melão. O estudo foi realizado no Perímetro Irrigado Senador Nilo Coelho em Petrolina -PE em um Argissolo Acinzentado. O delineamento experimental utilizado foi em blocos casualizados com 4 repetições. Os tratamentos constaram da aplicação, no sulco de plantio, de cinco compostos orgânicos (C.O.) preparados com diferentes tipos de resíduos. Foram avaliadas as propriedades químicas em dois períodos: tempo um (um ano após a implantação do experimento) e tempo dois (dois anos após a implantação do experimento), comparados ao tempo zero (antes da implantação do experimento). A adição de compostos promoveu melhorias na qualidade química do solo que foram evidenciadas por aumentos na maioria das características de fertilidade observadas, demonstrando a importância do uso sustentável do solo com a adição de compostos orgânicos

A 2d in vivo approach to study photosynthesis in grape berry

Is argued that fruit photosynthesis serves mainly as a respiratory CO2 refixation mechanism [1] but its contribution to growth and metabolism, localization and dynamics during fruit development are poorly known. Unlike the leaves, fruit volume imposes a constraint to photosynthesis by limiting light penetration. However, the patterns of chlorophyll distribution are apparently independent of a light intensity gradient. Microscopic observations of transversal slices of green stage grape berries (6-8 weeks after fruit set) of Alvarinho cultivar, revealed that exocarp cells, mesocarp cells next to vascular bundles, and seed coat cells present higher chlorophyll contents than inner mesocarp cells. The photosynthetic activity was determined on this material by Imaging-PAM fluorometry, a powerful tool for 2D mapping of in vivo photosynthesis. In 2 mm-thick grape berry discs, chlorophyll fluorescence parameters were estimated (Fv/Fm and II), and rapid light curves (RLC) were performed. Exocarp and seed coats of green berries showed the highest Fv/Fm values (ca. 0.6-0.7), and mesocarp cells around 85% of that value. Exocarp from mature grapes maintained Fv/Fm values during maturation, but in mesocarp and seed coats this value strongly decreased. ETRr were very sensitive to increasing light intensities and decreased with grape berry maturation. Our future prospects include the implication of photosynthesis on grape berry solute contents (sugars, acids), fruit and seed development.Fundação para a Ciência e a Tecnologia (research project no. PTDC/AGR-ALI/100636/2008

Microalgae hydrolysates as functional ingredients

Microalgae have been used in food and cosmetic industries due to their richness in compounds with high biological value, such as proteins, essential amino acids, vitamins and minerals [1]. Several microalgae contain high protein content, similar to other common protein sources such as meat and soybean [1], making them a promising source of bioactive peptides. Bioactive peptides are inert inside proteins but can show several interesting properties when isolated [2]. Antioxidant, antihypertensive, antidiabetic, anticancer, anti-inflammatory and anti-aging are some properties that can be found described in bioactive peptides. Bioactive peptides may be more easily absorbed by the gastrointestinal tract than the intact protein, which allied with their potential bioactivities make them interesting for the development of functional foods, with health benefits for the consumer. Hypertension is one of the main causes of cardiovascular diseases, which can lead to heart attack or stroke. Angiotensin-converting enzyme (ACE) is involved in blood pressure regulation, thus inhibiting it can help to control high blood pressure. Thus, this research aimed to produce water soluble hydrolysates rich in proteins and bioactive peptides, with antioxidant and anti-hypertensive potential, from the five microalgae species Chlorella vulgaris, Nannochloropsis oceanica, Tetraselmis sp., Scenedesmus obliquus and Phaeodactylum tricornutum. The five microalgae species were submitted to an enzymatic hydrolysis (one of the most described methods for producing bioactive peptides) with a cellulase and a subtilisin protease, using previously optimized methods. Prior to the enzymatic hydrolysis, C. vulgaris was submitted to an acid hydrolysis, using a weak and food-grade acid. The anti-hypertensive potential was evaluated by the hydrolysate’s ability of inhibiting ACE. Previous studies [3] showed that C. vulgaris and S. obliquus hydrolysates stood out with the higher antioxidant potential. All the hydrolysates demonstrated anti-hypertensive potential by showing an IC50 lower than 500 μg protein/mL for ACE inhibition (Table 1). Thus, production of peptide hydrolysates from microalgae may represent an interesting approach for the development of sustainable, natural functional ingredients to be used to prevent hypertension on the consumers by incorporating it in food matrices.In conclusion, the enzymatic hydrolysis of microalgae allowed to produce hydrolysates with antioxidant and anti-hypertensive potential. Further studies should be done to confirm the anti-hypertensive ability after the gastrointestinal digestion of the hydrolysates. If the bioactivity is maintained, these hydrolysates may be incorporated in food matrices as functional ingredients, contributing to the development of functional foods with antioxidant and anti-hypertensive benefits for the consumers.info:eu-repo/semantics/publishedVersio

Changes in soil fertility and mineral nutrition of mango orchards in São Francisco Valley, Brazil.

This research aimed to analyse the soil fertility changes and macronutrient concentration in mango plantations in Petrolina, Pernambuco, Brazil. Samples of soil were collected at depths of 0-20 and 20-40 cm, and leaves of mango trees during vegetative growth were collected from 11 areas with different cultivation time spans (6, 7, 8, 9, 10, 11, 14, 16, 17, 19, and 26 years). Nearby areas under natural vegetation were sampled for reference. The chemical characteristics of soil evaluated were: pH; P, K, Ca, Mg; exchangeable Na and Al; H + Al; organic matter; sum of bases; base saturation; and total cation exchange capacity. The mango leaves were analysed for N, P, K, Ca, and Mg. The agricultural management practices adopted by the mango-producing companies promoted changes in soil fertility when compared with the reference areas. The concentrations of organic matter tended to increase in the crop areas. The organic matter caused increases in CEC and nutrient retention. High P values were observed in soils and plants owing to the excessive use of fertilizers. This may cause nutritional imbalance and contamination of water sources. The contents of N, P, K in the leaves of mango trees were nutritionally adequat