Publisher: Embrapa Secretaria de Pesquisa e Desenvolvimento
Abstract: The objective of this work was to evaluate a recirculating aquaculture system using biological aerated filters in tanks for tambaqui (Colossoma macropomum) fingerlings farming, with two initial stocking densities (1.4 and 2.5 kg m-3). The biofilters had similar materials (media) and the same granulometric standards, but inverted orders of the media (classic and inverted). The following were monitored for 90 days: water quality; zootechnical, parasitological, and hematological parameters; and hematimetric indices. Water temperature, oxygen levels, pH, electrical conductivity, and dissolved solids concentration were compatible with tambaqui farming and did not differ between the different biofilters and densities. The ammonia and nitrite value was associated with the stocking densities and not with biofilter. The zootechnical and hematological parameters and the hematimetric indices evaluated were not influenced either by the type of biofilter or by the stocking densities. Ichthyophthirius multifiliis, Anacanthorus spathulatus, Notozothecium janauachensis, and Mymarothecium boegeri were the parasites found. The aerated, classical, and inverted biological filters have similar efficiency in maintaining water quality parameters for tambaqui fingerling farming. Resumo: O objetivo deste trabalho foi avaliar um sistema de recirculação de água com uso de filtros biológicos aerados em tanques de criação de alevinos de tambaqui (Colossoma macropomum), com duas densidades de estocagem (1,4 e 2,5 kg m-3). Os biofiltros possuíam materiais semelhantes (meios) e os mesmos padrões granulométricos, mas com a ordem dos meios invertida (clássico e invertido). Foram monitorados durante 90 dias: a qualidade da água; os parâmetros zootécnicos, parasitológicos e hematológicos; e os índices hematimétricos. A temperatura da água, os níveis de oxigênio, o pH, a condutividade elétrica e a concentração de sólidos dissolvidos foram compatíveis com a produção de tambaqui e não diferiram entre os diferentes biofiltros e densidades. O valor de amônia e nitrito foi associado à densidade de estocagem e não ao biofiltro. Os parâmetros zootécnicos e hematológicos e os índices hematimétricos avaliados não foram influenciados nem pelo tipo de biofiltro nem pela densidade de estocagem. Ichthyophthirius multifiliis, Anacanthorus spathulatus, Notozothecium janauachensis e Mymarothecium boegeri foram os parasitas encontrados. Os filtros biológicos aerados, clássico e invertido têm similar eficiência na manutenção de parâmetros de qualidade de água para o cultivo de alevinos de tambaqui.
This study investigated the effects of floor and cage rearing systems on performance, meat quality, and enteric microorganisms of male and female yellow feather broilers. Two hundred Xueshan chickens (42 days old; 100 of each sex) were divided into four groups, according to sex and rearing system (stainless-steel cage or litter floor). Male and cage-reared broilers exhibited better (P0.05) by rearing system. The enteric microbiota assessment by 16S rRNA amplicon-based sequencing showed that Firmicutes, Proteobacteria, and Bacteroidetes were the most prevalent phyla in both rearing systems, and that the cecum was relatively stable in terms of microbiome composition. Floor-reared broilers exhibited a richer diversity of bacteria in the intestinal tract than cage-reared broilers, while alpha diversity was not significantly different (P>0.05) among the groups. The ratio of Bacteroidetes to Firmicutes and the abundance of Helicobacter and Romboutsia could potentially affect the production of broilers. These findings indicate that cage rearing improved the production of male Xueshan broilers, which may be due to the difference in enteric microbiota between cage and floor rearing systems.
Abstract Soil organic carbon (SOC) is a great component of the global carbon cycle and plays significant role in terms of climatic changes and agricultural land-use. An important management concern is the extent of SOC stocks sequestration when farmland is converted to forest stands. We have reviewed the literature about changes in SOC stock in relation to altitude and stand age and sought differences between former agricultural land and origin forest stands. Accumulation of SOC was monitored in 17 examples (41 samples) in 9 locations across the all Czech Republic with focus on the main tree species Norway spruce (Picea abies [L.] Karst.). Results showed a significant increase of SOC stock in an afforested farmland with increasing stand age. Another factor was the altitude. With increasing altitude, the carbon stock in our model gradually decreased. From the data analyzed comparing forest stand and former agricultural land, similar carbon sequestration was documented for both variants with higher SOC for forest stands. However, other conditions affecting SOC stock should be taken into consideration, especially silvicultural management, topography, disturbances, soil properties and cultivation. The general tendencies of SOC changes at the investigated sites are comparable to those in other studies across the Europe.
Herbicide resistance is becoming more common in weed ecotypes and crop species including turfgrasses, but current gaps in knowledge limit predictive ecological risk assessments and risk management plans. This project examined the effect of annual glyphosate applications on the vegetative growth and reproductive potential of two weedy bentgrasses, creeping bentgrass (CB) and redtop (RT), where the glyphosate resistance (GR) trait was mimicked by covering the bentgrass plants during glyphosate application. Five field plots were studied in habitats commonly inhabited by weedy bentgrasses including an agricultural hayfield, natural meadow, and wasteland. Results showed that annual glyphosate treatment improved bentgrass survivorship, vegetative growth, and reproductive potential compared with bentgrass in unsprayed subplots. In the second year of growth, RT plants had an 86-fold increase in flower number in glyphosate-treated subplots versus controls, while CB plants had a 20-fold increase. At the end of the three year study, plant community composition had changed in glyphosate-treated subplots in hayfield and meadow plots compared to controls. Soils in subplots receiving glyphosate had higher nitrate concentrations than controls. This is the first study to mimic the GR trait in bentgrass plants with the goal of quantifying bentgrass response to glyphosate selection pressure and understanding the impacts on surrounding plant communities.
The environmental impact of different land-use systems for energy, up to the farm or forest ¿¿gate¿¿, has been quantified with Life Cycle Assessment (LCA). Four representative crops are considered: OilSeed Rape (OSR), Miscanthus, Short-Rotation Coppice (SRC) willow and forest residues. The focus of the LCA is on changes in Soil Organic Carbon (SOC) but energy use, emissions of GreenHouse Gases (GHGs), acidification and eutrophication are also considered. In addition to providing an indicator of soil quality, changes in SOC are shown to have a dominant effect on total GHG emissions. Miscanthus is the best land-use option for GHG emissions and soil quality as it sequesters C at a higher rate than the other crops, but this has to be weighed against other environmental impacts where Miscanthus performs worse, such as acidification and eutrophication. OSR shows the worst performance across all categories. Because forest residues are treated as a by-product, their environmental impacts are small in all categories. The analysis highlights the need for detailed site-specific modelling of SOC changes, and for consequential LCAs of the whole fuel cycle including transport and use. JRC.H.1-Water Resources
A study of comparison of water vapor mixing ratio profiles, relative humidity profiles, and cloud vertical structures using two different instruments, a multiwavelength Aerosol-Depolarization-Raman lidar and radiosoundings, is presented. The observations were taken by the lidar located in Warsaw center and the radiosoundings located about 30km to the North in Legionowo (Poland). We compared the ground-based remote sensing technology with in-situ method in order to improve knowledge about water content thought the atmosphere and cloud formation. The method used for retrieving the cloud vertical structure can be improved comparing the radiosonde results with the lidar observations, which show promising results.
International audience; Cedar is an emblematic Mediterranean forest tree. Genetic research activities on Mediterranean Cedrus species are progressively developed in relation to conservation, restoration, and exploitation plans of these forest tree species. However, currently available molecular biology tools supporting genetic research in these fields are still scarce and have a limited genetic resolution potential. We developed a new set of 12 nuclear microsatellite markers (nSSRs) on Cedrus atlantica that we combined with four previously developed ones in three multiplexes. We checked their monogenic inheritance in controlled crosses. We used a collection of 131 samples from six populations of C. atlantica to estimate null allele frequencies and probability of identity and to characterize the structure of genetic diversity in the fragmented distribution range of this species. We also tested the transferability of the markers to another set of 36 samples from the other Mediterranean Cedrus species and performed a phylogenetic analysis. The three multiplexes reached a high level of resolution potential that we used to evaluate sampling quality. Null allele frequency estimates showed no specific pattern across populations or across species and did not affect the results of biogeographic and phylogenic analyses. Our results reveal a very clear geographical genetic structure within C. atlantica, and the phylogenic tree matched previous analyses based on other markers. Our results confirm the potential interest of these nSSR multiplexes for genotyping in Cedrus.
Publisher: Chinese Society for Horticultural Science (CSHS) and Institute of Vegetables and Flowers (IVF), Chinese Academy of Agricultural Sciences (CAAS)
Abstract The combination of the relatively open plant canopy and slow growth, especially at early growth stages, results in lower competitiveness of black seed (Nigella sativa L.) than weeds. Thus, weed interference is known as an important factor affecting black seed yield. Therefore, to determine the critical period of weed control and its effects on nutrients uptake of black seed field experiments were conducted in 2011 and 2012. Two quantitative series of weed removal treatments including weed-infested and weed-free treatments were implemented from black seed emergence to maturity harvest. To determine critical period of weed control, plots were weed-infested or weed-free for 0, 14, 28, 42, 56, 70 days after emergence, in weed-infested and weed-free treatments, respectively. The results revealed that N, P and K contents in weed tissues significantly increased with increasing weed-infested periods during both years of the experiment. The reduction in grain and oil yield due to longer periods of weed-infested conditions or shorter periods of weed-free conditions were accompanied by simultaneous reduction of N, P and K uptake in black seed grains and tissues. Overall, N, P and K contents in weed tissue were found to be 1.8 to 2 times higher than that of black seed. It was concluded that 58 or 49 days weed-free periods are required to avoid yield loss (above 5% or 10%) in black seed.