Extractable iron and organic matter in the suspended insoluble material of fog droplets

In this work the formation and composition of aggregates between metals and organic material is studied in real fog samples. In a preliminary experiment it has been found that concentrated cloud samples form a yellow-brown precipitate in the presence of Fe(III). Standards of humic acids and fulvic acids co-precipitate with Fe(III), forming similar aggregates i.e. iron-humates (Fe-HA) and iron-fulvates (Fe-FA). By comparing the solubility properties of aggregates by extracting organic carbon (OC) in different pH conditions, it has been observed that fog droplet particulate samples are characterised by solubility properties more similar to those of Fe-HA than Fe-FA. Dilute alkaline solutions can also easily extract organic refractory substances that form aggregates with metals. The recoveries of the total extractable organic matter (accounting for 12% of total insoluble carbon and 15% of particulate mass) are similar to those of humic-like substances (HULIS) from particulate samples. The chromatographic behaviour and functional group characteristics measured in the alkali-extract fraction of precipitated aggregates with iron and in the insoluble particulate of fog samples, are those of humic-like material. Thus, soluble HULIS are able to interact with iron to form particulate, but the composition of a large fraction of insoluble organic carbon is still unknown. These findings have implications on the solubility and surface tension properties of fog droplets and can therefore potentially influence droplet formation, as well as cloud chemical and photochemical processes.     

Mycorrhizal communities in relation to biomass production and nutrient use efficiency in two varieties of Douglas fir (Pseudotsuga menziesii var. menziesii and var. glauca) in different forest soils

To investigate the role of arbuscular and ectomycorrhizas for growth and nutrition, Douglas fir (Pseudotsuga menziesii), a species capable of establishing both types of symbioses, was used. Seedlings of two varieties of Douglas fir, var. menziesii (DFM) and var. glauca (DFG), differing in biomass production under non-mycorrhizal conditions, were planted in two soils of different nutrient status without preceding Douglas fir cultivation. After 2 years, the abundance of ectomycorrhizas was significantly higher on DFM than on DFG roots and higher in nutrient rich than in poor soil. Independent of the abundance of ectomycorrhiza colonization, roots of both Douglas fir varieties contained in most cases a minimum of six to nine different fungal species identified by ITS sequencing, which displayed both soil- and seed origin-specific patterns. Rhizopogon vinicolor was associated with DFM, whereas Cadophora finlandia, Sebacinaceous sp., Tricholoma sp. and a Tuber sp. were more frequently found on DFG roots. Ectendomycorrhizas were also identified and included under ectomycorrhiza for determination of nutrient relations. Net primary productivity and nitrogen-use efficiency were positively correlated with the degree of ectomycorrhiza colonization of Douglas fir seedlings suggesting that nitrogen accumulation did not keep pace with biomass production despite increased ectomycorrhizal colonization. Phosphorus-use efficiency was negatively correlated with the abundance of arbuscular mycorrhizas, suggesting higher efficiency of these fungi than of ectomycorrhizas for phosphorus supply to the host. DFM, which had higher inherited growth capacities than DFG, displayed higher ectomycorrhizal colonization than DFG. In our experimental design the physiology of the host tree and soil properties, but not the diversity of fungi present on roots, were decisive factors for formation and abundance of ectomycorrhiza.     

Seeding date influence on camelina seed yield, yield components, and oil content in Chile

Camelina (Camelina sativa L.) was introduced for the first time in Chile in 2008 as a potential feedstock for biodiesel and also as high omega-3-containing seed oil for the salmon feed industry. The objective of this study was to determine the optimum seeding date to maximize camelina seed yield in South Central Chile. The experiment was conducted under dryland conditions in Chillán, El Carmen, Los Angeles, Gorbea, and Osorno in 2008 and in Chillán and Los Angeles in 2009. The experimental design was a RCB with a split-plot arrangement with four replicates, where the main plot was the seeding date (five dates) and the sub-plot the spring type cultivars (Gold of Pleasure, Suneson, and Blaine Creek). Seeding dates at each environment were targeted to 30 April, 15 May, 30 May, 30 June, and 30 July of 2008 and 2009. The combined analysis of variance indicated no cultivar main effect or interactions with cultivar. The date by environment interaction was significant for seed yield. There were no seed yield differences among seeding dates in Chillán and El Carmen. The first three seeding dates were the highest yielding in Los Angeles and Osorno, and only the first seeding date was significantly higher in seed yield in Gorbea. Highest seed yield at Los Angeles, Gorbea, and Osorno were 1995, 1310, and 2314 kg ha⁻¹. Seed oil content was not different among seeding dates in Chillán and El Carmen. Highest seed oil content occurred at Osorno and Gorbea on the first three seeding dates and ranged from 420 to 457 g kg⁻¹. Spring camelina cultivars are well adapted to South Central Chile as a winter annual crop when seeded before 15 May except in Osorno when seeded before 30 May. No disease or insectpests were observed except for Aster Yellow infestation at Chillán and Los Angeles. Camelina has great potential as an oilseed for biodiesel and as a source of omega-3 for the pharmaceutical industry but markets for it need to be developed locally for camelina to become an option for growers.     

Effect of Calcium Foliar Application on the Characteristics of Blueberry Fruit during Storage

ABSTRACT

Effect of calcium (Ca) foliar application on blueberry fruit characteristics during storage was investigated. Calcium applications began 28 d after flowering, two levels (3.9 g Ca^{2 +} and 39 g Ca^{2 +}) and a control without calcium were used (0.0; 3.0, and 30 mL L^?1). The fruits were harvested on day 103 and were stored for 56 d at 2 ± 1°C. At harvest time the fruits had a significant statistical different concentration, which were maintained until the last day of storage. The fruit from the 30 mL L^?1 treatment was the highest. The lowest texture levels are found with the treatment without calcium, which shows a statistically significant change from storage day 29. The LMP percentage did not varied in the fruit from the treatment with 30 mL L^?1, but did in the fruit without calcium. Hunter L, b, and the index chromes were influenced by the applied calcium levels, significantly greater at 30 mL L^?1; and by the time of storage in the fruits with treatment of 30 mL L^?1.     

Effect of Foliar Application of Calcium on the Quality of Blueberry Fruits

Effect of foliar application of calcium (0.78 g, 4.68 g, and 7.8 g Ca^{2 +}) in pre-harvest, at three different growing conditions (tunnel, mesh, and ambient), on texture and pectin in blueberries (Vaccinium corymbosum) was studied. Calcium contents in leaves as well in fruits were different (P ≤ 0.05), affected by growing conditions and time. Differences (P ≤ 0.05) in calcium content were found in tunnel cultivar fruit, during the period to cell expansion toward harvest, at calcium foliar level of 5 mL per L (7.8 g). Fruit texture was significantly higher at the beginning of the cell expansion period in the tunnel cultivar fruit, and a linear correlation between calcium concentration and texture was established. Increment in low methoxyl pectin (LMP) was influenced by growing conditions, and was different (P ≤ 0.05) for tunnel cultivar fruit. A good correlation between LMP and calcium content was obtained with the high dose of calcium (5 mL per L).     

梨韧皮部特异表达启动子AtSUC2驱动下的GUS基因的转化和表达

 以 ‘Old Home’ 梨无菌苗叶片为外植体, 利用根癌农杆菌介导将专一在韧皮部表达启动子AtSUC2 驱动下的GUS 基因转入 ‘Old Home’中。筛选出了‘Old Home’ 梨叶片高效遗传转化的最佳条件：农杆菌和外植体在液体培养基上共培比在固体培养基上共培转化率提高5倍。 PCR分析和Southern 杂交鉴定表明GUS 基因已整合到转基因植株的基因组中,组织化学检测和Western 杂交鉴定证明了GUS 基因在转基因植株韧皮部中的表达。     

Root architecture characteristics of plant inlay in live slope grating

In the experimental garden of the Department of Soil Bioengineering and Landscape Construction, University of Applied Life Sciences in Vienna, Austria, coarse root systems of three different brush species were completely excavated and semi-automatically digitized. The species were Lonicera xylosteum, Ligustrum vulgare and Euonymus europaeus. The 3-D root ar-chitectures reveal different growth strategies between species, which are related to ecological characteristics and physical soil proper-ties. The root architecture of Lonicera xylosteum and Ligustrum vulgare, planted in the under layer of the live slope grading, where the soil is very tight and the soil water content and fertility are relatively low, is shallow. However, the root distribution of E. eu-ropaeus, planted in the middle layer, where environmental conditions are better, is deeper. Most of the root biomass of the three spe-cies is concentrated in the 0-30 cm soil layer. A quarter of the root biomass of Ligustrum vulgare is distributed in the upper layer of the plant inlay. E. europaeus has a relatively even distribution in the 30-60 cm and 60-90 cm soil layer.     

Perception and acceptance of agricultural production in and on urban buildings (ZFarming): a qualitative study from Berlin,Germany

Rooftop gardens, rooftop greenhouses and indoor farms (defined as ZFarming) have been established or planned by activists and private companies in Berlin. These projects promise to produce a range of goods that could have positive impacts on the urban setting but also carry a number of risks and uncertainties. In this early innovation phase, the relevant stakeholders’ perceptions and social acceptance of ZFarming represent important preconditions for success or failure of the further diffusion of this practice. We used the framework of acceptance to investigate the stakeholders’ attitudes and to identify the key factors that might hinder or promote the introduction of ZFarming. The results are based on an analysis of 38 qualitative interviews conducted with key stakeholders in Berlin. As the results show, major perceived benefits of ZFarming include improved consumer awareness, education, and the creation of experimental spaces. Stakeholders further perceive opportunities for resource savings, new business models, repurposing of abandoned buildings and improved aesthetics. Major perceived risks are associated with growing techniques that are considered “unnatural”, health risks (due to urban pollutants), conflicts with images of traditional agriculture, the rejection of animal production in urban areas, the risk of projects being too expensive and too complex or being implemented too early, i.e. before the mechanisms are fully understood. The analysis further reveals which contextual factors—political, legal, market-related, spatial or societal—might negatively or positively influence ZFarming acceptance.     

The origin of aluminum flocs in polluted streams

About 240,000 square kilometers of Earth's surface is disrupted by mining, which creates watersheds that are polluted by acidity, aluminum, and heavy metals. Mixing of acidic effluent from old mines and acidic soils into waters with a higher pH causes precipitation of amorphous aluminum oxyhydroxide flocs that move in streams as suspended solids and transport adsorbed contaminants. On the basis of samples from nine streams, we show that these flocs probably form from aggregation of the epsilon -Keggin polyoxocation AlO4Al12(OH)24(H2O)12(7+)(aq) (Al13), because all of the flocs contain distinct Al(O)4 centers similar to that of the Al13 nanocluster.