Mycorrhizal Enhancement of Biomass Productivity of Big Bluestem and Switchgrass in Neutral and Acidic Substrate

Objectives: Greenhouse pot studies were conducted to assess the abilities of two arbuscular mycorrhizal fungi (AMF) namely, Rhizophagus clarus (Rc) and R. intraradices (Ri) to enhance biomass productivity of big bluestem (Andropogon gerardii), as a complementary bioenergy feedstock to and switchgrass (Panicum virgatum).Methodology and results: Big bluestem (BB) and switchgrass (SG) were grown in a soilless substrate adjusted to pH=6.5 or 4.5 and inoculated separately with Rc and Ri. Plants were grown in the greenhouse for 12 weeks. Results show that AMF significantly enhanced biomass productivity of the grasses over corresponding controls, regardless of pH. Substrate inoculation with Rc produced the highest and similar total BB biomass at pH=6.5 and 4.5. However, biomass partitioning into shoot and root differed with pH. Inoculation with Ri produced the highest and similar total SG biomass at pH=6.5 and 4.5. SG biomass was more equally distributed at both pHs.Conclusion and application of findings: Differences in substrate partitioning into shoot and root biomass shown by Rc-inoculated BB at 4.5, appeared to be consistent with Rc endowing BB the capacity to maintain both relatively high shoot as well as root biomass at pH=4.5. This pattern of substrate partitioning was not shown by Rc- or Ri-inoculated BB grown at pH =6.5, or Ri-inoculated BB grown at pH=4.5. Neither was the pattern shown by Rc- or Ri-inoculated SG, which maintained relatively similar R/S ratios regardless of pH. The usual biomass partitioning by BB at pH=4.5 deserves further investigation. Different patterns of biomass partitioning notwithstanding, results of this study strongly suggest that BB could complement SG, the model biofuel feedstock, especially under acidic substrate conditions.Key words: Big bluestem; switchgrass; biofuel feedstock; arbuscular mycorrhizae, substrate acidity

Participation in household decision making and justification of wife beating: evidence from the 2018 Mali Demographic and Health Survey

BackgroundWe assessed the association between women's participation in household decision making and justification of wife beating among married women ages 15-49 y in Mali.MethodsWe employed a cross-sectional study design among 7893 women of reproductive age involving a two-stage sampling technique using version 6 of the Mali Demographic and Health Survey (MDHS) data, which was conducted in 2018.ResultsApproximately 37% participated in at least one household decision while 23.4% reported that they would not justify wife beating in any of the stated circumstances. Women who participated in at least one household decision had lower odds (adjusted odds ratio [AOR] 0.834 [confidence interval {CI} 0.744 to 0.935]) of justifying wife beating. With respect to the covariates, we found that women 45-49 y of age had lower odds of justifying wife beating compared with those ages 15-19 y (AOR 0.569 [CI 0.424 to 0.764]). Women with higher education (AOR 0.419 [CI 0.265 to 0.662]) and those whose husbands had secondary education (AOR 0.825 [CI 0.683 to 0.995]) had lower odds of justifying wife beating. Women who lived in urban areas were less likely to justify wife-beating (AOR 0.328 [CI 0.275 to 0.390]) compared with those who lived in rural areas.ConclusionThis study suggests that participation in household decision making is associated with a significantly lower rate of justifying wife beating in Mali. These results underscore the need for various interventions to empower women to increase women's participation in decision making to reduce justification of domestic violence

Exploitation of Rhizosphere Microbiome Services

The rhizosphere is a soil hot spot where, due to a tight plant-bacteria interaction, plants recruit a beneficial microbiome, enhancing its density and activity. Rhizosphere microbial communities have the potential to provide several services, and their management and \u201cengineering\u201d can be exploited to set up agro-environmental biotechnologies. In this chapter, after a brief overview of the array of services that we can obtain from rhizosphere beneficial microbiome, two case studies are presented: i) the exploitation of plant growth promoting bacteria to increase plant tolerance to drought, potentially able to improve crop plants yields in arid and semi-arid lands, ii) the exploitation of plant biostimulation effect over degrading microbial populations in the rhizosphere, sustaining phyto-rhyzo-remediation approaches in PCB contaminated soils. In each case study the experimental settings, the in vitro and in vivo tests, the result evaluation and modelling are reported, together with a discussion of the critical issues

Phytoremediation using native plants

The unprecedented growth in industrialization has significantly increased pollution in the environment causing public health concerns. The remediation of various contaminated environmental matrices presents a global challenge. Phytoremediation using native plants can serve a dual purpose of site remediation and ecological restoration. Native plants provide an ideal residence for microbial community in their rhizosphere with enzymatic ability to accumulate, stabilize, biodegrade or volatilize various inorganic and organic contaminants. A case study that compared a native plant, Chromolaena odorata, from crude oil-polluted land in Nigeria against a referenced plant, Medicago sativa, for polycyclic aromatic hydrocarbons (PAHs) remediation is presented in this chapter. It was observed that the native plant thrived, tolerated and degraded PAHs better than the reference plant but with no significant difference in PAH degradation. The use of plants is well suited to its natural contaminated area and solar-driven, prevents erosion and eliminates secondary airborne and waterborne waste but with some challenges. Phytoremediation using native species may be effective and efficient than its non-native counterparts, and it is ecologically safer, cheaper, aesthetically pleasing, socially acceptable and easier to cultivate. Native plants in phytoremediation can be further enhanced and improved using molecular techniques to optimize the harvest time, reduce growth duration and increase biomass production and root depth