Biodegradation of Organic Matter During Mechanical Biological Treatment of MSW

The German Technical Guideline for Municipal Solid Waste (TASI) stipulates criteria for waste to be landfilled in order to minimize environmental hazards and landfill maintenance. One of these requirements is an ignition loss of less than five percent dm (dry matter). Only waste which has been incinerated can comply with this criterion, and subsequently be landfilled. Experts agree that the ignition loss alone is not suitable to predict reactions in a landfill. Therefore, other methods of assessing biological activity of processed MSW in a landfill are presented and discussed. It was found that respiration activity was most appropriate for such an assessment at this stage. From available data, it was concluded that processed MSW is fit for landfilling if the respiration activity is below 5 mg O₂/g dm over a period of 96 hours.     

Natural abundance of 18O of sugar biomarkers in topsoils along a climate transect over the Central Scandinavian Mountains,Norway

Precipitation and topsoil samples from a climate transect over the Scandinavian Mountains, Norway, were analyzed for bulk and compound‐specific δ¹⁸O values. The natural abundance of ¹⁸O in the plant‐derived hemicellulose biomarkers arabinose and xylose correlates positively with δ¹⁸O of bulk soil, but not with δ¹⁸O of precipitation. This suggests that other factors than δ¹⁸O_prec, such as evaporative ¹⁸O enrichment of leaf water, exert a strong influence on the natural abundance of ¹⁸O in soils.     

Short‐term response of the Ca cycle of a montane forest in Ecuador to low experimental CaCl2 additions

The tropical montane forests of the E Andean cordillera in Ecuador receive episodic Sahara‐dust inputs particularly increasing Ca deposition. We added CaCl₂ to isolate the effect of Ca deposition by Sahara dust to tropical montane forest from the simultaneously occurring pH effect. We examined components of the Ca cycle at four control plots and four plots with added Ca (2 × 5 kg ha^–1 Ca annually as CaCl₂) in a random arrangement. Between August 2007 and December 2009 (four applications of Ca), we determined Ca concentrations and fluxes in litter leachate, mineral soil solution (0.15 and 0.30 m depths), throughfall, and fine litterfall and Al concentrations and speciation in soil solutions. After 1 y of Ca addition, we assessed fine‐root biomass, leaf area, and tree growth. Only < 3% of the applied Ca leached below the acid organic layer (pH 3.5–4.8). The added CaCl₂ did not change electrical conductivity in the root zone after 2 y. In the second year of fertilization, Ca retention in the canopy of the Ca treatment tended to decrease relative to the control. After 2 y, 21% of the applied Ca was recycled to soil with throughfall and litterfall. One year after the first Ca addition, fine‐root biomass had decreased significantly. Decreasing fine‐root biomass might be attributed to a direct or an indirect beneficial effect of Ca on the soil decomposer community. Because of almost complete association of Al with dissolved organic matter and high free Ca²⁺ : Al³⁺ activity ratios in solution of all plots, Al toxicity was unlikely. We conclude that the added Ca was retained in the system and had beneficial effects on some plants.     

Discriminant analysis of selected yield components and fatty acid composition of chosen Triticum monococcum, Triticum dicoccum and Triticum spelta accessions

This study analyses the variability of key yield components, the content of protein and crude fat in grain and the fatty acid composition of 50 spring accessions of Triticum monococcum, Triticum dicoccum and Triticum spelta of various origins. The average protein content of the grain of T. monococcum was 20.8%, of T. dicoccum 19.7%, and of spelt 17.0%. The crude fat content of T. monococcum grain (2.7%) was significantly higher compared with T. spelta (2.4%) and T. dicoccum (2.3%). In crude fat, fatty acids C18:2, C18:1 and C16 predominated. T. spelta was characterised by the highest concentrations of C18:2 and C16 (55.89% and 18.77% respectively), while T. monococcum had the highest content of C18:1 (26.35%). The structure of analysed fatty acids proved to be highly desirable in this species. A discriminant analysis performed separately for five variables: protein and fat content and three biometrical characters and separately for fatty acid composition enabled three Triticum species to be distinguished. These species also differed significantly with respect to the C18:1/C16 ratio which was equal to 1.78, 1.06, 1.47 and 0.99 in T. monococcum, T. dicoccum, T. spelta and Triticum aestivum respectively.     

Local vs. formal breeding and inbred line vs. synthetic cultivar for organic farming: Case of Vicia faba L.

As organic farming refrains from the use of agrochemical inputs, it is characterized by large environmental heterogeneity. Genotype × location interaction is expected to be larger across organic cropping areas than across conventional ones. When breeding for organic farming, it is important to identify an adequate breeding approach and type of cultivar. The objective was to investigate in the case of faba bean (Vicia faba L.) the effectiveness of local breeding (exploiting local adaptation) vs. formal breeding (exploiting broad adaptation) for grain yield in organic farming and to compare the performance of two types of cultivars: inbred lines and synthetics. A set of 18 inbred lines, their polycross progenies and 13 checks was tested in five locations in Germany from 2004 to 2006. Due to the large genotype × location interaction, local breeding generated higher gains from selection than formal breeding. Based on estimates of genotypic performance and variance of inbred lines and polycross progenies, the best synthetic cultivar at generation Syn-1 and the best inbred line cultivar were predicted. Despite the large variance among inbred lines available in local breeding, the highest performing entry in both breeding strategies was a synthetic, due to its partial realization of heterosis.     

Development of locally-adapted faba bean cultivars for organic conditions in Germany through a participatory breeding approach

Organic farming requires cultivars that are specifically adapted to this low input cropping system. Hence, organic farmers and scientists joined in a participatory breeding approach to develop region-specific genotypes of spring faba bean for organic conditions in Germany. A set of 49 genotypes with contrasting degrees of heterozygosity and heterogeneity was used in field trials across five locations in Germany during 3 years 2004, 2005 and 2006. The material involved 18 inbred lines, their 18 polycross progenies, one blend of inbred lines, one blend of polycross progenies, one blend of hybrids and ten checks. Inbred lines are uniform, thus giving the option to be specifically adapted; whereas the polycross progenies and synthetics (Syn-1; predicted from the inbred lines and polycross progenies performance) are partly heterogeneous and heterozygous, thus giving the option to evolve. Agronomic performance was assessed and a “personal appreciation” score of the material was assigned to each genotype by each partner. This personal appreciation was strongly influenced by biotic and abiotic constraints faced by the crop in each location and by the expected grain yield of the genotypes. Uniformity was apparently appreciated by organic farmers. In all locations, the highest yielding inbred line yielded slightly better than the predicted highest yielding synthetic. However, this slight disadvantage of the synthetic is very likely to disappear if the synthetic (Syn-1) is propagated during successive generations.     

Effect of hardening on frost tolerance and fatty acid composition of leaves and stems of a set of faba bean (<Emphasis Type="Italic">Vicia faba</Emphasis> L.) genotypes

Frost tolerance is a main component of winter-hardiness and improving it would promote faba bean (Vicia faba L.) cropping in cool-temperate regions. In many species, leaf fatty acid composition was found to be related to frost tolerance. The objective of this study was to determine, in a representative sample of genotypes, the effect of hardening on leaf and stem (1) frost tolerance and (2) fatty acid composition, and to seek correlations between them. First leaf, second leaf and stem of 31 faba bean genotypes were analyzed after hardening and without hardening. High frost tolerance of known winter genotypes and several experimental lines was shown. Hardening had a significant, positive effect on frost tolerance of all three organs. Stems were on average more frost tolerant than leaves. Hardening induced significant changes in the fatty acid composition: oleic acid decreased significantly in leaves by 3.24% and in stems by 1.77%, whereas linolenic acid increased in leaves by 6.28% and in stems by 9.06%. In stems, correlations between frost tolerance and fatty acid composition were not significant. Correlation coefficients strongly indicated that non-hardened oleic acid content, changes in oleic acid and in linoleic plus linolenic acid content in leaves partly explained their frost tolerance; 0.347 (P < 0.1) < |r| < 0.543 (P < 0.01). The results corroborate the importance of using genetic differences in the fatty acid metabolism in breeding grain legumes for frost tolerance.