Nitrogen dynamics in soil solution under different land uses: Atlantic forest and cacao–cabruca system

In the southern region of Bahia, a large portion of the Atlantic Forest was occupied by the cacao–cabruca system, which is implemented after the complete removal of the understory vegetation without altering the canopy. The objective of this study was to determine the nitrogen concentration in the soil solution in two micro-basins; one with the cacao–cabruca system and one in the Atlantic forest in the southern region of the state of Bahia. Samples were collected weekly during two periods, from September to December 2012 and from April to June 2013, using sample extractors installed in the micro-basins at 15, 45 and 90 cm. The inorganic forms in the soil solutions were analyzed through ion chromatography, total nitrogen was analyzed using spectrophotometry and mineralization and nitrification rates were analyzed using the laboratory incubation method. Among the nitrogen forms analyzed in the cacao–cabruca soil solution, the dissolved organic nitrogen prevailed among the rain classes in the three depths. In the forest, nitrate predominated at 15 cm, while the organic nitrogen prevailed in the other depths. The highest mineralization and nitrification rates were recorded in the forest. Of the inorganic nitrogen forms analyzed in the soil, ammonium concentrations showed higher rates than nitrate in both areas. Low inorganic nitrogen concentrations in the cabruca soil solution are associated with low mineralization and nitrification rates. Thus we can conclude that even if some studies point towards the environmental efficiency of this system, there are differences in the N forms in the forest and cacao–cabruca areas.     

The Effect of Contrasting Moistening Regimes on CO<Subscript>2</Subscript> Emission from the Gray Forest Soil under a Grass Vegetation and Bare Fallow

The effect of contrasting moisture regimes on the CO₂ emission from the gray forest soils (Haplic Luvisols (Loamic, Cutanic, Humic)) under a grass vegetation and bare fallow was studied in a field simulation experiment in June–September, 2015 (Moscow region). Two short soil droughts (53 and 34 days) and a long one (94 days) were simulated on plots isolated from precipitation. A variant with regular irrigation, where the soil moisture was maintained 60–70% of their water holding capacity, was used as a control. Over the whole observation period, the CO₂ emissions from the soils studied decreased by a factor of 1.8 compared to the control only in the variant with the grass vegetation under prolonged drought. During the first hours after irrigation of the dry plots, the soil respiration intensified due to the “Birch effect”. The magnitude of this effect was 84–104% in the soils under the grass vegetation and 114–133% in the fallow areas. Owing to this phenomenon, the total CO₂ emission from the soils subjected to two short droughts was equal to the CO₂ flux under regular moistening for the grass plots and exceeded it by almost 1.3 times for the fallow plots as compared to the control. However, the share of extra CO₂ flux induced by moistening of the dry soils did not exceed 8–10% of the total CO₂ emission over the whole observation period.     

Estimated Reduction in Solids During Sheep Bedding Composting as a Function of the Composition of the Organic Fractions

The different organic matter fractions of residues significantly impact the degradability of organic material in composting windrows. Based on that, this study aimed to find out the organic matter fractions that most impact the breakdown rate during composting, besides proposing models to estimate the solids reductions in sheep bedding composting windrows. To that end, 24 sheep beddings from different locations and varied composition were composted so as to ensure the representativeness of the sample. The models found for reduction in total (TS) and volatile (VS) solids as a function of compostable organic matter (COM) and organic matter resistant to composting (OMRC) were not significant. Lignin had correlation coefficients of ?0.6, ?0.89, and ?0.84 in relation to temperature, TS reduction, and VS reduction, respectively. The hemicellulose:lignin ratio was the parameter most correlated with temperature (0.69), TS reduction (0.91), VS reduction (0.92), and nitrogen (0.5), which led to more significant predictive models. It can be concluded that the hemicellulose:lignin ratio is the parameter that most impacts the breakdown of organic matter and nitrogen losses in sheep bedding composting windrows.     

Reproductive fluids,used for the in vitro production of pig embryos,result in healthy offspring and avoid aberrant placental expression of PEG3 and LUM

Background: In vitro embryo production(IVP) and embryo transfer(ET) are two very common assisted reproductive technologies(ART) in human and cattle. However, in pig, the combination of either procedures, or even their use separately, is still considered suboptimal due to the low efficiency of IVP plus the difficulty of performing ET in the long and contorted uterus of the sow. In addition, the potential impact of these two ART on the health of the offspring is unknown. We investigated here if the use of a modified IVP system, with natural reproductive fluids(RF) as supplements to the culture media, combined with a minimally invasive surgery to perform ET, affects the output of the own IVP system as well as the reproductive performance of the mother and placental molecular traits.Results: The blastocyst rates obtained by both in vitro systems, conventional(C-IVP) and modified(RF-IVP), were similar.Pregnancy and farrowing rates were also similar. However, when compared to in vivo control(artificial insemination, AI),litter sizes of both IVP groups were lower, while placental efficiency was higher in AI than in RF-IVP. Gene expression studies revealed aberrant expression levels for PEG3 and LUM in placental tissue for C-IVP group when compared to AI,but not for RF-IVP group.Conclusions: The use of reproductive fluids as additives for the culture media in pig IVP does not improve reproductive performance of recipient mothers but could mitigate the impact of artificial procedures in the offspring.     

Voice,capacity, awareness: Early career ocean professionals’ perspectives on the equitable implementation of the Biodiversity Beyond National Jurisdiction Agreement

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Effect of Steeping Conditions (Sulfur Dioxide,Lactic Acid,and Temperature) on Starch Yield,Starch Quality,and Germ Quality from the Intermittent Milling and Dynamic Steeping Process (IMDS) for a Brazilian Corn Hybrid

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