Terrestrial Production Systems Research Articles

Os herbicidas causam impactos na sobrevivência e desenvolvimento de abelhas?

A polinização é um serviço ecossistêmico chave na manutenção da biodiversidade, essencial no processo reprodutivo das plantas superiores em quase todos os sistemas produtivos terrestres. Para que se possa manter a vasta biodiversidade global, incluindo de espécies cultivadas, é necessária que haja diversidade de polinizadores. No entanto, as abelhas sofrem com as ações antrópicas. Estes insetos vêm desaparecendo de áreas agrícolas devido à introdução de espécies exóticas, às grandes áreas de monocultivo, ao desmatamento para agricultura e pastagem e, principalmente, à fragmentação de habitats e ao uso excessivo ou incorreto de defensivos agrícolas. Esses pesticidas podem afetar não só a longevidade das abelhas, como também sua vitalidade o que pode, ao longo do tempo, influenciar na manutenção das colônias. No caso do uso de defensivos agrícolas, a maioria dos estudos visa avaliar os efeitos dos inseticidas sobre as abelhas, sendo escassos os estudos sobre outras classes de produtos, como os herbicidas. Esta revisão buscou dar foco aos possíveis efeitos, especialmente, de uso de herbicidas na sobrevivência e no desenvolvimento das abelhas. O uso de herbicidas que apresentam toxicidade para os insetos benéficos, como glyphosate, 2,4-D, MSMA e paraquat devem ser continuamente monitorado. As doses subletais dos herbicidas, ou seja, dose menor do que a que provoca a morte, podem provocar alterações comportamentais nos indivíduos, acarretando em sérios prejuízos à manutenção das colônias.

The race for highly productive microalgae strains

Evaluation of: Huerlimann R, de Nys R, Heimann K. Growth, lipid content, productivity, and fatty acid composition of tropical microalgae for scale-up production. Biotechnol. Bioeng. 107(2), 245–257 (2010).Microalgae-derived biodiesel is considered a highly promising next-generation biofuel, as current fossil fuel reserves are being depleted and combusted causing GHG emissions. Microalgae are arguably the most efficient renewable biofuel source to cover our current and future demand without competing for arable land or natural areas rich in biodiversity. Microalgae are sunlight-driven organisms that convert CO2 to starch and a variety of lipids with applications such as biofuels, foods, animal feeds and high-value bioactive products. The critical parameters affecting species selection for biodiesel production are growth rate, lipid content, lipid productivity and fatty acid composition. Previous research papers and review articles commonly discuss growth parameters of single species, but few report a comprehensive comparison of several microalgae and provide data for lipid productivity in terms of g m-2 day-1 as done by Huerlimann et al. This allows for a direct comparison of microalgal lipid productivity to terrestrial production systems; thus making comparisons between volumetric and area productivity of lipids possible, which is necessary for large-scale production. Distinctively, Huerlimann et al. also study the effects of different growth media on lipid production and composition during different growth phases.

Some Unorthodox Thoughts: What Western Agriculture Should Learn from Chinese Agriculture

Starting from the experience of research carried out in Hubei, subtropical intensive agricultural area of China, I focus on some aspects that make this agricultural and cultural system different and peculiar from Western countries. Reducing the length of food-webs supporting human population, integrating aquatic and terrestrial production systems; having had insects such as silkworm and plants such as soybeans as key factors in the production of proteins and fiber. Herbivory of fishes and adoption of husbandry made by small animals coupled with a very limited use of ruminants such as cow and buffalo are among the many strategies developed by the Chinese culture and their peculiar history. Many of these strategies that have permitted supporting an immense population can be better considered by Western countries.

Some Unorthodox Thoughts: What Western Agriculture Should Learn from Chinese Agriculture

Starting from the experience of research carried out in Hubei, subtropical intensive agricultural area of China, I focus on some aspects that make this agricultural and cultural system different and peculiar from Western countries. Reducing the length of food-webs supporting human population, integrating aquatic and terrestrial production systems; having had insects such as silkworm and plants such as soybeans as key factors in the production of proteins and fiber. Herbivory of fishes and adoption of husbandry made by small animals coupled with a very limited use of ruminants such as cow and buffalo are among the many strategies developed by the Chinese culture and their peculiar history. Many of these strategies that have permitted supporting an immense population can be better considered by Western countries.