Physicochemical Characteristics of Biochars Derived From Corn,Hardwood, Miscanthus,and Horse Manure Biomasses

Biochar, a carbon-rich by-product of biomass pyrolysis, is widely recognized as a potential ingredient for soil amendment, fertility, and carbon sequestration owing to its favorable physicochemical properties. The objective of this study was to investigate the chemical and physical properties of biochars produced through pyrolysis at 450°C from agricultural residues available in Northwest Missouri, namely hardwood (HW), corn stover (CR), miscanthus (MS), and horse manure (HM). These properties were assessed through the analysis of pyrolysis yield, pH, volatile matter, fixed carbon, ash and carbon (C), hydrogen (H), sulfur (S), nitrogen (N) contents, trace metal concentrations, surface morphology, surface functional groups, bulk density, and water holding capacity. The biochars derived from HW, MS and CR materials showed high volatile-matter (33–42%), high fixed carbon contents (42–47%), very low ash contents (6–15%), and low bulk density (0.14–0.28 g cm^?3) as compared to that of HM. A wide range of trace elements was observed in biochar samples with significant differences in concentrations. In addition, CR, HW and MS biochars displayed a disordered graphitic-like structure with well-developed pores and surface areas of 23, 70 and 90 m²/g respectively, and high water-holding capacity up to 750%, indicating their potential application as a soil amendment.     

Morpho-physiological Response of Saffron (Crocus Sativus L.) to Particle Size and Rates of Zinc Fertilizer

A field study was conducted during 2015–2017 in order to evaluate effects of the foliar application of different sources and concentrations of zinc oxide (ZnO) on the yield and morpho-physiological characteristics of saffron. Experimental treatment included the foliar application of nano ZnO at a concentration of (3, 6, and 9 g L^?1), foliar application of normal ZnO at a concentration of (3, 6, and 9 g L^?1) and the control. Both types of ZnO had positive effects on the saffron yield and number of flowers, but the highest yield and flower number were obtained by the foliar application of 9 g L^?1 normal ZnO followed by 6 g L^?1 nano ZnO. Increasing concentrations of both fertilizers up to 3 g L^?1 had no significant effect on crocin, but the crocin content significantly decreased at higher concentrations. Effects of experimental treatments were significant on all morpho-physiological traits. The maximum chlorophyll a (1.74 mg.g^?1) was observed in normal ZnO at a concentration of 9 g L^?1 followed by nano ZnO at a concentration of 3 g L^?1. The increasing application of different types of fertilizers linearly increased the Peroxidase activity, but the highest activity of Catalase in normal ZnO and nano ZnO was measured after the foliar application at concentrations of 3 and 6 g L^?1, respectively.     

Evaluation of Nitric Acid Extraction of Elements from Soils and Sediments in Two watersheds in East Tennessee

Determining the total elemental concentrations of soils requires a total dissolution method, in which hydrofluoric acid (HF) is commonly used. However, this method is tedious and risky due to the dangerous reagent HF. This study compared a single acid extraction technique using a nitric acid (HNO₃) extraction method to total dissolution (HF + microwave assisted aqua regia) for evaluating the total elemental concentrations in soils and sediments. The two methods were used to analyze the elemental content of soils and sediments from the Oostanaula Creek and Pond Creek watersheds in East Tennessee. Twenty-one elements (Al, Ba, Ca, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Nd, P, S, Si, Sr, Ti, V, Zn, and Zr) were subsequently measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The extraction efficiency for HNO₃ relative to the total was compared and discussed. In general, HNO₃ can extract the elements in absorbed phases and those residing in non-silicate minerals. Six elements (Ba, Co, Fe, Ca, Mn, and P) generated significant correlations between total and HNO₃ in both OC and PC watersheds. Finally, the elements were grouped according to the interrelationships of their total elemental concentrations based on the dendrogram plots, suggesting their geochemical association in soils and sediment forming minerals.     

An artificial inoculation protocol for Uromycladium acaciae,cause of a serious disease of Acacia mearnsii in southern Africa

Uromycladium acaciae is the cause of a severe wattle rust epidemic in plantations of Acacia mearnsii (black wattle) in southern Africa. Research on the biology of this damaging rust is assisting in the development of control strategies. One strategy under investigation is the identification and deployment of resistant lines of A. mearnsii. Selection of resistant families currently relies on large-scale, time-consuming and expensive field trials. In this study, we present a detailed artificial inoculation protocol for U. acaciae, which can be used to screen for resistance. The results of an experiment that used the protocol to screen the relative resistance of 12 families of A. mearnsii to U. acaciae are also presented. The developed artificial inoculation protocol can also be used to investigate several other aspects of this host–pathogen system.     

Identification of powdery mildew resistance loci in wheat by integrating genome-wide association study(GWAS) and linkage mapping

Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development.A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism(SNP)markers.The association panel was evaluated for reactions to three Bgt inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15.Linkage disequilibrum(LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb, and population structure analysis revealed seven subgroups in the panel.Association analysis using a mixed linear model(MLM) identified three loci for powdery mildew resistance on chromosome 2 B, designated QPm.stars-2BL1,QPm.stars-2BL2, and QPm.stars-2BL3.To evaluate the efficacy of GWAS in gene discovery,QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI420646 × OK1059060-126135-3.Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an interval where QPm.stars-2BL2 was located, lending credence to the GWAS results.QPm.stars-2BL1 and QPm.stars-2BL3, which were associated with four SNPs located at 457.7–461.7 Mb and two SNPs located at 696.6–715.9 Mb in the Chinese Spring reference IWGSC RefSeq v1.0, respectively, are likely novel loci for powdery mildew resistance and can be used in wheat breeding to improve powdery mildew resistance.     

A comparison of four dietary assessment methods in materially deprived households in England

OBJECTIVES: Low-income households in the UK concentrate factors associated with poor record-keeping such as lower literacy, numeracy and English language skills. The present study aimed to (1) compare the validity and acceptability of three dietary survey methods against appropriate reference measures and (2) identify a method which was both valid and acceptable in low-income households. DESIGN: Cross-sectional design comparing three 4-day dietary survey methods (multiple-pass 24-hour recall, food checklist and semi-weighed method) against a 4-day weighed inventory and other reference measures within subjects. SETTING: London, UK, 2001. SUBJECTS: Low-income households were selected using a doorstep screening questionnaire in 18 of the 60 most deprived neighbourhoods in London. Results are based on 384 respondents (159 males, 225 females) aged 2-90 years in 240 households. Respondents were mainly White (48%), Black or Black British (31%) or Asian or Asian British (9%). RESULTS: The dietary survey method preferred by interviewers was the 24-hour recall. Most respondents preferred the food checklist. Compared with the weighed inventory, repeat 24-hour recalls and the food checklist yielded higher estimates of energy and nutrient intakes. The semi-weighed method was least liked and yielded the lowest estimates of intake. CONCLUSIONS: Based partly on evidence presented here and partly on evidence to be presented in later publications, four multiple-pass 24-hour recalls were recommended as the most appropriate method for a national study of diet and nutrition in low-income households in the UK.     

A landscape model for quantifying the trade-off between conservation needs and economic constraints in the management of a semi-natural grassland community

We present a landscape model to investigate the ecological consequences and costs of different management regimes in semi-natural grasslands. The model integrates dynamic abiotic conditions, management (i.e. disturbance) regime and response of more than 50 characteristic plant and insect species by modelling the dynamics of relevant niche parameters as predictors for species distribution models. We compare our results for exemplary scenarios differing in spatial and temporal scales and exemplary species belonging to different functional groups through several steps of aggregation.Our analysis aims at the question whether an infrequent massive disturbance by rototilling can serve as a less expensive alternative to annual mowing for preserving the characteristic species composition of open dry grasslands in Southern Germany. Rototilling results in a shifting mosaic determining the habitat quality for plant and animal species that may reduce the survival of local or regional populations.For some meadow species as well as the encroaching shrub species, rototilling has a detrimental effect on regional habitat quality. Other species, e.g. weeds and annual pioneers, strongly benefit or show only negligible reaction. Since this is a multi-objective problem, there is a no magic bullet in selecting an optimum scenario of measures. But by visualising the trade-off between ecological consequences and costs, our model is a valuable tool for conservation managers providing a sound scientific basis for management decisions relying on available ecological knowledge. It is also an interesting example for a model describing complex communities in a relatively simple way, simultaneously considering the main driving factors.     

Pomegranate phenolics from the peels, arils, and flowers are antiatherogenic: studies in vivo in atherosclerotic apolipoprotein e-deficient (E 0) mice and in vitro in cultured macrophages and lipoproteins

We have analyzed in vivo and in vitro the antiatherogenic properties and mechanisms of action of all pomegranate fruit parts: peels (POMxl, POMxp), arils (POMa), seeds (POMo), and flowers (POMf), in comparison to whole fruit juice (PJ). Atherosclerotic E 0 mice consumed POM extracts [200 microg of gallic acid equivalents (GAE)/mouse/day] for 3 months. Blood samples, peritoneal macrophages (MPM), and aortas were then collected. All POM extracts possess antioxidative properties in vitro. After consumption of PJ, POMxl, POMxp, POMa, or POMf by E (0) mice, the atherosclerotic lesion area was significantly decreased by 44, 38, 39, 6, or 70%, respectively, as compared to placebo-treated group, while POMo had no effect. POMf consumption reduced serum lipids, and glucose levels by 18-25%. PJ, POMxl, POMxp, POMf, or POMa consumption resulted in a significant decrement, by 53, 42, 35, 27, or 13%, respectively, in MPM total peroxides content, and increased cellular paraoxonase 2 (PON2) activity, as compared to placebo-treated mice. The uptake rates of oxidized-LDL by E (0)-MPM were significantly reduced by approximately 15% after consumption of PJ, POMxl, or POMxp. Similar results were obtained on using J774A.1 macrophage cell line. Finally, pomegranate phenolics (punicalagin, punicalin, gallic acid, and ellagic acid), as well as pomegranate unique complexed sugars, could mimic the antiatherogenic effects of pomegranate extracts. We conclude that attenuation of atherosclerosis development by some of the POM extracts and, in particular, POMf, could be related to the combined beneficial effects on serum lipids levels and on macrophage atherogenic properties.     

Microorganisms as driving factors for the community structure of testate amoebae along an altitudinal transect in tropical mountain rain forests

We investigated microbial biomass, fungal biomass and microbial community structure at three altitudes (1000, 2000 and 3000 m) and in two soil layers [L/F layer (Layer I) and underlying H/Ah layer (Layer II)] of tropical mountain rain forests in southern Ecuador. Basal respiration, microbial biomass and concentration of ergosterol generally declined from Layer I to Layer II and peaked at 2000 m. Compared to temperate forest ecosystems microbial biomass and ergosterol concentrations were generally low. Patterns in phospholipid fatty acids indicated that the composition of microbial communities markedly changed from Layer I to Layer II. These differences between layers decreased with increasing altitude. The concentration of the arbuscular mycorrhizal fungal marker PLFA 16:1ω5c decreased with altitude in Layer I but increased in Layer II. The fungal-to-bacterial ratio increased with altitude and was higher in Layer I than in Layer II. Presumably, low microbial biomass in soils of tropical forest ecosystems is due to high temperature associated with high respiration but also low litter quality, with the latter declining with altitude. These conclusions are supported by the fact that at higher altitude the microbial community changed from a bacterial-dominated to a fungal-dominated system. CCA showed that microbial biomass correlated closely with density of a number of putatively bacterial feeding testate amoeba species including Corythion dubium Taranek, 1871, Euglypha cristata Leidy, 1879, Trigonopyxis arcula Penard, 1912, Tracheleuglypha dentata Deflandre, 1928 and Trinema lineare Penard, 1890. Ergosterol concentrations, but not the PLFA 18:2ω6c, strongly correlated with the putatively fungal feeding species Phryganella acropodia (Hertwig, Lesser, 1874) Hopkinson, 1909. Generally, parallel to microbial biomass and ergosterol concentrations the density of testate amoebae peaked at 2000 m. However, compared to microbial parameters changes in testate amoebae communities between two layers were less pronounced. The data suggest that density and community structure of testate amoebae are driven by the availability of food resources (bacteria and fungi) which at high altitude decrease with increasing moisture and decreasing pH.