Sabine Zikeli

Initial soil development in lignite ash landfills and settling ponds in Saxony-Anhalt, Germany

Weathering and initial soil formation was investigated on 5 sites of lignite ash disposal differing in age (5 to 30 years) and methods of disposal (landfills and sluicing to settling ponds). Soils developed on lignite ash derived substrates were characterized by low bulk densities ( 100) in subsoils. Initiale Bodenbildung in Braunkohlenaschedeponien und Spulteichen in Sachsen-Anhalt Fur die vorliegende Untersuchung wurden 5 Flachen ausgewahlt, die aus Braunkohlenaschesubstraten unterschiedlichen Alters (5—30 Jahre) und unterschiedlicher Deponierungsart (Verkippung und Verspulung) bestehen. Anhand dieser Beispiele werden die durch Verwitterung induzierten Veranderungen der Aschen beschrieben. Die Boden auf den Untersuchungsflachen haben folgende Eigenschaften: sehr niedrige Lagerungsdichten ( 100 dominiert.

Organic Farming and Organic Food Quality: Prospects and Limitations

This review provides an introduction to organic farming, its history and concepts, organic certification systems and governmental support, impacts to the environment and food security, the quality of organic food, and the impact of organic farming on human health. Organic farming is a holistic approach to agriculture and food systems that is based on agroecosystem health, soil fertility, reduction of inputs, and locally to regionally adapted farming systems. The first organic ideas were developed after World War I in Europe as an alternative to the existing conventional farming systems which induced rapid and crucial social and environmental changes in rural areas. Today, organic farming is growing rapidly on a global scale, with around 370 million hectares currently under certified organic management and a turnover of organic products amounting to 60 billion US dollars. Given that organic farming has environmental benefits, some governments are subsidizing organic farmers, while others establish legally valid organic standards that must be followed to enhance consumer trust in organic labeling.

Centaurium erythraea Cultivation Method for Optimal Yield and Product Quality

ABSTRACT The effect of cultivation methods on plant development, yield, secoiridoid glycoside content, and physical and microbiological contamination of centaury (Centaurium erythraea) were investigated. Plants were cultivated in uncovered soil, soil covered with mulch film, or in pots. There was no difference in dry matter yield of plants grown on a mulch film (665 g.m–2) and without mulch film (680 g.m–2), whereas the outdoor cultivation in pots resulted in lower yield (330 g.m–2). The physical and microbiological contamination was lowest in plants cultivated in pots and highest when cultivated without soil cover. The total concentration of secoiridoid glycosides in the plants was not affected by the cultivation methods. The use of mulch film combined high yield and low microbiological and physical contamination, and had no effect on the content of desired bioactive compounds.

Is Bhutan destined for 100% organic? Assessing the economy-wide effects of a large-scale conversion policy

Organic agriculture (OA) is considered a strategy to make agriculture more sustainable. Bhutan has embraced the ambitious goal of becoming the world’s first 100% organic nation. By analysing recent on-farm data in Bhutan, we found organic crop yields on average to be 24% lower than conventional yields. Based on these yield gaps, we assess the effects of the 100% organic conversion policy by employing an economy-wide computable general equilibrium (CGE) model with detailed representation of Bhutan’s agricultural sector incorporating agroecological zones, crop nutrients, and field operations. Despite a low dependency on agrochemicals from the onset of this initiative, we find a considerable reduction in Bhutan’s GDP, substantial welfare losses, particularly for non-agricultural households, and adverse impacts on food security. The yield gap is the main driver for a strong decline in domestic agricultural production, which is largely compensated by increased food imports, resulting in a weakening of the country’s cereal self-sufficiency. Current organic by default farming practices in Bhutan are still underdeveloped and do not apply the systems approach of organic farming as defined in the IFOAM organic farming standards. This is reflected in the strong decline of nitrogen (N) availability to crops in our simulation and bears potential for increased yields in OA. Improvement of soil-fertility practices, e.g., the adoption of N-fixing crops, improved animal husbandry systems with increased provision of animal manure and access to markets with price premium for organic products could help to lower the economic cost of the large-scale conversion.

Agronomic performance of new open pollinated experimental lines of broccoli (Brassica oleracea L. var. italica) evaluated under organic farming

In order to develop new open pollinating cultivars of broccoli for organic farming, two experiments were conducted during fall 2015 and spring 2016. This study was aimed at comparing the agronomic performance of eleven new open pollinating breeding lines of broccoli to introduce new lines and to test their seasonal suitability for organic farming. Field experiments were carried out at the organic research station Kleinhohenheim of the University of Hohenheim (Stuttgart-Germany). Different agronomic traits total biomass fresh weight, head fresh weight, head diameter, hollow-stem, fresh weight harvest index and marketable yield were assessed together with commercial control cultivars. The data from both experiments were analyzed using a two-stage mixed model approach. In our study, genotype, growing season and their interaction had significant effects on most traits. Plants belonging to the fall growing season had bigger sizes in comparison to spring with significantly (p< 0.0001) higher biomass fresh weight. Some experimental lines had significant lower head fresh weight in spring in comparison to the fall season. The high temperature during the harvest period for the spring season affected the yield negatively through decreasing the firmness of broccoli heads. The low average minimum temperatures during the spring growing season lead to low biomass fresh weight but high fresh weight harvest index. Testing the seasonal suitability of all open pollinating lines showed that the considered fall season was better for broccoli production. However, the change in yield between the fall and the spring growing season was not significant for “Line 701” and “CHE-MIC”. Considering the expression of different agronomic traits, “CHE-GRE-G”, “Calinaro” and “CAN-SPB” performed the best in the fall growing season, and “CHE-GRE-G”, “CHE-GRE-A”, “CHE-BAL-A” and “CHE-MIC” and “Line 701” were best in the spring growing season, specifically due to the highest marketable yield and proportion of marketable heads.

Quality aspects in open-pollinated onion varieties from Western Europe

Commercial onion breeders limit their selection criteria by focusing almost exclusively on conventional farming. This raises the demand for certain well known varieties, but lowers the general diversity available on the mainstream market. A way to maintain biodiversity is to preserve old open-pollinated varieties. Through their distinct aroma and flavor, these plants are again drawing the interest of farmers and consumers alike, making them a viable alternative to commercial varieties. To assess yield and quality aspects of West-European open-pollinated onions, we have evaluated nine varieties and compared them against two of their commercial, well-established counterparts. The study included onion production on the field in South-West Germany, evaluation of the quality and flavor parameters, as well as a trained sensory taste panel. Results showed high diversity in yield and chemical properties of the studied onion varieties, where two varieties in particular, stood out significantly. Compared to the control, the variety “Birnformige” performed best and demonstrated high concentrations of fructan and pyruvic acid, both known to have curative and medicinal properties. On the other end of the spectrum, the variety “Jaune des Cevennes” demonstrated low dry matter content, low concentration of enzymatically-produced pyruvic acid and a high bolting percentage. The study also confirmed the link between individual quality components in onion bulbs, including the significantly negative correlation between minerals (such as calcium and magnesium) and fructan.

Development of a near-infrared spectroscopy method (NIRS) for fast analysis of total, indolic, aliphatic and individual glucosinolates in new bred open pollinating genotypes of broccoli (Brassica oleracea convar. botrytis var. italica)

This study describes the development of near-infrared spectroscopy (NIRS) calibration to determine individual and total glucosinolates (GSLs) content of 12 new-bred open-pollinating genotypes of broccoli (Brassica oleracea convar. botrytis var. italica). Six individual GSLs were identified using high-performance-liquid chromatography (HPLC). The NIRS calibration was established based on modified partial least squares regression with reference values of HPLC. The calibration was analyzed using coefficient of determination in prediction (R2) and ratio of preference of determination (RPD). Large variation occurred in the calibrations, R2 and RPD due to the variability of the samples. Derived calibrations for total-GSLs, aliphatic-GSLs, glucoraphanin and 4-methoxyglucobrassicin were quantitative with a high accuracy (RPD=1.36, 1.65, 1.63, 1.11) while, for indole-GSLs, glucosinigrin, glucoiberin, glucobrassicin and 1-methoxyglucobrassicin were more qualitative (RPD=0.95, 0.62, 0.67, 0.81, 0.56). Overall, the results indicated NIRS has a good potential to determine different GSLs in a large sample pool of broccoli quantitatively and qualitatively.