Changes in physical and biological soil quality indicators in a tropical crop system (Havana, Cuba) in response to different agroecological management practices

A Framework to Incorporate Biological Soil Quality Indicators into Assessing the Sustainability of Territories in the Ecuadorian Amazon

In Amazonian Ecuador, land-use change from tropical rainforest to different productive purposes is leading to irreversible situations from an environmental perspective. The objective of this paper was to highlight the significance of the biological components in the soils in Amazonian Ecuador, and the importance of considering biological soil quality indexes when assessing environmental impacts in the soils of tropical Pan-Amazonian areas. Since the literature on the subject is dispersed and inaccessible, a bibliographic review was conducted, with the aim of compiling protocols and proposals for practical utilization. We compiled tables, including specific indicators from the biological point of view. We present the available methods for assessing the sustainability of Amazonian territories through the analysis of soil quality. Our contribution facilitates an edaphic perspective to be taken into account in decision-making processes for sustainable territorial development.

Silkworm pupae oil exerts hypercholesterolemic and antioxidant effects in high-cholesterol diet-fed rats

BACKGROUND

Silkworm pupae is a good resource of edible oil that is especially rich in unsaturated fatty acids and is considered to be an excellent dietary supplement for hyperlipidemia.

RESULTS

Groups fed a high-cholesterol diet (HCD) with silkworm pupae oil (SPO) supplementation (1, 2, or 4 mL kg^-1  day^-1 ) orally had significantly lower levels of serum total cholesterol (P < 0.05) and low-density lipoprotein cholesterol (P < 0.05) compared to the HCD group. With regard to antioxidant parameters, except for levels of glutathione peroxidase (GSH-Px) in the liver, 2 and 4 mL kg^-1  day^-1 of SPO supplementation leaded to higher total antioxidant capacity (P < 0.05), superoxide dismutase (P < 0.05) and GSH-Px levels (P < 0.05), as well as lower malondialdehyde levels (P < 0.05), both in serum and liver compared to the HCD group.

CONCLUSION

The results of the present study indicate that supplementation with SPO can improve lipid profiles and alleviate oxidative stress in high-cholesterol diet-fed rats. © 2016 Society of Chemical Industry.

Fatty acid composition of canola (Brassica napus L.), as affected by agronomical, genotypic and environmental parameters

Vegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. There is not any data on the effects of tillage practices on fatty acid composition of canola (Brassica napus L.). Hence, in a 2-year split plot experiment, the effects of different tillage systems (no (NT), minimum (MT) and conventional tillage (CT)), canola genotypes (Hyola 401 (V1) and PF (V2)) and sowing dates (including Sep. 8, 23 and Oct. 7) on the fatty acid composition of canola were evaluated. Tillage practices and the combination of canola genotypes and sowing dates were randomized to the main and sub-plots, respectively. The highest oleic acid content was the result of combining NT, V1 and Sep. 23, and the lowest was related to the combination of CT, V2 and Oct. 7. While the combination of NT, V1 and D1 resulted in the highest amount of unsaturated fatty acids, this amount was the lowest for the combination of CT, V2 and Sep. 23. For the selection of an appropriate canola producing strategy, all these parameters must be taken into account. The combination of NT, V1 and Sep. 23 may be the most favorable cropping strategy for canola production under a Mediterranean climate.

Ranking the magnitude of crop and farming system effects on soil microbial biomass and genetic structure of bacterial communities

Biological soil characteristics such as microbial biomass, community structures, activities, and functions may provide important information on environmental and anthropogenic influences on agricultural soils. Diagnostic tools and detailed statistical approaches need to be developed for a reliable evaluation of these parameters, in order to allow classification and quantification of the magnitude of such effects. The DOK long-term agricultural field experiment was initiated in 1978 in Switzerland for the evaluation of organic and conventional farming practices. It includes three representative Swiss farming systems with biodynamic, bio-organic and conventional fertilization and plant protection schemes along with minerally fertilized and unfertilized controls. Effects on microbial soil characteristics induced by the long-term management at two different stages in the crop rotation, i.e. winter wheat after potato or corn, were investigated by analyzing soil bacterial community structures using analysis of PCR-amplified rRNA genes by terminal restriction fragment length polymorphism and ribosomal intergenic spacer analysis. Application of farmyard manure consistently revealed the strongest influence on bacterial community structures and biomass contents. Effects of management and plant protection regimes occurred on an intermediate level, while the two stages in the crop rotation had a marginal influence that was not significant.