Bound amino acids in humic acids from arable cropping systems

We investigated the varying concentrations of bound amino acids in humic acids (HA) extracted from soils under both crop rotation and continuous cropping of rye. The experiment was created in 1957. Since then, winter rye had been grown continuously and also the sequence of the 7 yr rotation had been started: potato, spring barley, alfalfa, alfalfa, oil seed rape, winter rye, and winter rye. Soils were fertilized with NPK and manure. Continuous cropping of rye increased total acidity of soils and the contents of carboxylic and phenolic groups in HA. The total amounts of the bound amino acids in HA from soils under crop rotation were higher than from continuous cropping of rye. Fertilization with NPK increased the contents of bound amino acids more than manure. Neutral amino acids dominated in all samples of HA, and basic amino acids had the lowest concentrations. In both types of cultivation, glutamic acids, glycine, alanine, valine, and lysine dominated. The proline contents in HA from continuous rye cropping were higher than in HA from soils under crop rotation. The concentrations of β‐alanine and lysine were higher in HA from crop rotation indicating a higher microbial biomass since these compounds are typical constituents of bacteria cell walls.     

Isolation and identification of novel pyranoanthocyanins from black carrot (Daucus carota L.) juice

Six novel pyranoanthocyanins were identified by HPLC-ESI-MSn in black carrot (Daucus carota L. ssp. sativus var. atrorubens Alef.) juice. The two major compounds, namely, the vinylcatechol adducts of cyanidin 3-O-(6-O-feruloyl-beta-D-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside and cyanidin 3-O-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, respectively, were isolated by a combination of high-speed countercurrent chromatography with semipreparative HPLC. Their structures were fully elucidated by means of one- and two-dimensional NMR spectroscopy and high-resolution mass spectrometry. The four remaining pigments were characterized as the vinylphenol and vinylguaiacol adducts of cyanidin 3-O-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, the vinylguaiacol adduct of cyanidin 3-O-(6-O-feruloyl-beta-D-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside, and the vinylcatechol adduct of cyanidin 3-O-(6-O-sinapoyl-beta-d-glucopyranosyl)-(1-->6)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-galactopyranoside. These compounds are formed during storage of the juice through the direct reaction of either caffeic, ferulic, or coumaric acid with the respective genuine anthocyanins.     

Effect of cultivation and within-field differences in soil conditions on feral Helianthus annuus growth in ridge-tillage maize

Differences in weed population dynamics with respect to within-field heterogeneity are not well documented despite increasing interest in site-specific management of agro-ecosystems. The focus of this study was to determine if mechanical weed management (cultivation) and/or soil factors help to explain observed within-field distributions of feral common sunflower (Helianthus annuus L.). The ridges and furrows created by the ridge–tillage system adds additional microsites to existing spatial heterogeneity for soil characteristics such as soil organic carbon (SOC) concentration. Experimental areas were selected on the basis of naturally high or low SOC concentration. Cultivation resulted in 100% mortality of H. annuus seedlings growing in the middle of furrows. Cultivation of pre-emergence herbicide treated and no-herbicide ridges resulted in small but statistically significant ( = 0.05) reductions in seedling survival. No differences were detected in H. annuus canopy height, stem diameter, stem length, or vegetative biomass between high and low SOC environments. Neither total reproductive biomass (P = 0.49) nor the biomass of flowers near physiological maturity (an estimate of fecundity; P = 0.59) were affected by SOC environment. Late season H. annuus lodging was observed to reduce reproductive biomass. Juvenile plants that survived mechanical weed control efforts grew and produced reproductive biomass similarly across SOC environments. The lack of difference in vegetative and reproductive characteristics between high and low SOC environments suggests that SOC (or the edaphic conditions associated with greater or lesser SOC level) was not critical in contributing to the observed distribution of H. annuus from juvenile to flowering stages of growth within well-fertilized, irrigated agricultural habitats.     

Element contents of spruce needles (P. abies [L.] Karst.) along an altitudinal gradient in the bavarian alps

One and 3 yr old needles of (Picoa abies [L.] Karst) were analyzed for mineral content and to determine the main nutrients and pollutants. In the Bavarian Alps 70 adult spruce trees were selected along an altitudinal gradient on seven stands from 800 to 1720 m above sea level. The samples, collected at different times of the year, came from the tops of the crowns. The needle analysis showed a severe P and a mild N deficiency. Samples which were washed with chloroform have significantly lower Fe and Ph contents. The low S concentrations of the needles exclude a burden by air pollution caused by SO₂.     

Variations in the acid content of rain water in the course of a single precipitation

The major acid components in the rain water collected during five different rainfall events in July and August 1977, were found to be a strong acid, the weak acid NH _in4 ^su+ and dissolved CO₂ from the atmosphere. Variations in their concentrations were determined as a function of time in the course of each of the rainfall events. Two experimental methods were used in this investigation, a microtitrim etric method and a coulometric method, and the data were analyzed by the use of modified Gran functions. Both methods gave the same results. The most significant observation was that the strong acid concentration increased from very low values to a maximum and then decreased in the course of a single rainfall event.     

Urbanization as a major cause of biotic homogenization

When measured by extent and intensity, urbanization is one of the most homogenizing of all major human activities. Cities homogenize the physical environment because they are built to meet the relatively narrow needs of just one species, our own. Also, cities are maintained for centuries in a disequilibrium state from the local natural environment by the importation of vast resources of energy and materials. Consequently, as cities expand across the planet, biological homogenization increases because the same “urban-adaptable” species become increasingly widespread and locally abundant in cities across the planet. As urbanization often produces a local gradient of disturbance, one can also observe a gradient of homogenization. Synanthropic species adapted to intensely modified built habitats at the urban core are “global homogenizers”, found in cities worldwide. However, many suburban and urban fringe habitats are occupied by native species that become regionally widespread. These suburban adapters typically consist of early successional plants and “edge” animal species such as mesopredator mammals, and ground-foraging, omnivorous and frugivorous birds that can utilize gardens, forest fragments and many other habitats available in the suburbs. A basic conservation challenge is that urban biota is often quite diverse and very abundant. The intentional and unintentional importation of species adapted to urban habitats, combined with many food resources imported for human use, often produces local species diversity and abundance that is often equal to or greater than the surrounding landscape. With the important exception of low-income areas, urban human populations often inhabit richly cultivated suburban habitats with a relatively high local floral and faunal diversity and/or abundance without awareness of the global impoverishment caused by urbanization. Equally challenging is that, because so many urban species are immigrants adapting to city habitats, urbanites of all income levels become increasingly disconnected from local indigenous species and their natural ecosystems. Urban conservation should therefore focus on promoting preservation and restoration of local indigenous species.     

Nutrition education for illiterate children in southern Madagascar--addressing their needs, perceptions and capabilities

OBJECTIVE: A Knowledge, Attitudes and Practices (KAP) study was conducted in three villages of Bekily District in southern Madagascar prior to the implementation of a health education programme with children. The participatory learning concept of the Child-to-Child approach was followed to involve the children in the planning and implementation of the programme, which was covered by the German Agency for Technical Cooperation. DESIGN: To this effect, qualitative research methods such as Participatory Learning and Action techniques (focus group discussions, mapping and matrix ranking, etc.) were applied. SUBJECTS: The survey was conducted between August and December 1999. It involved a total of 55 school-aged children (6-14 years) along with 21 mothers and 34 fathers, representing different ethnic groups and educational backgrounds. RESULTS: The results show that children's KAP related to health and nutrition strongly reflect those of adults. They are not aware of a possible link between bad hygiene and the occurrence of diseases. According to them, diarrhoea or malaria is caused by consuming too large amounts of certain foods. Even if they know about certain elementary hygiene behaviours, they do not practise this in their everyday life. CONCLUSION: A major objective of the health education programme for children should be to tackle the discrepancy between hygiene-related knowledge and behaviour. Through the participatory study approach the children revealed their ability to contribute to the programme development. In using appropriate communication channels, the Child-to-Child health education programme is expected to influence the health behaviours of both adults and children. The health education programme should be combined with a literacy programme to address the children's desire to learn reading and writing.     

Microbial activity and bacterial composition of H2-treated soils with net CO2 fixation

The effects of H₂ gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO₂ dynamics and microbial activity and composition were analyzed. The H₂ emission rate of 250 nmol H₂ g⁻¹ soil h⁻¹ was similar to the upper limit of estimated H₂ amounts emitted from N₂ fixing nodules into the surrounding soil ([Dong, Z., Layzell, D.B., 2001. H₂ oxidation, O₂ uptake and CO₂ fixation in hydrogen treated soil. Plant and Soil 229, 1-12.]). After 1 week of H₂ supply to soil samples simultaneously with H₂ uptake net CO₂ production declined continuously and this finally led to a net CO₂ fixation rate in the H₂-treated soil of 8 nmol CO₂ g⁻¹ soil h⁻¹. The time course of H₂ uptake and CO₂ fixation in the soils corresponded with an increase in microbial activity and biomass of the H₂-treated soil determined by microcalorimetric measurements, fluorescence in situ hybridization analysis (FISH) and DNA staining (DAPI). Shifts in the bacterial community structure caused by the supply of H₂ were recorded. While the H₂ treatment stimulated β-and γ-subclasses of Proteobacteria, it had no significant effect on α-Proteobacteria. In addition, FISH-detectable bacteria of the Cytophaga-Flavobacterium-Bacteroides phylum increased in numbers.