Temperate Climate Of Central Europe Research Articles

Planting for the Urban Rain—Vegetation in Urban Bioretention Systems for Stormwater Management under Temperate Climate Conditions—A Systematic Review

Weather extremes such as heavy rainfall and long periods of drought brought about by climate change put a strain on the environment and people. Cities can counter these weather extremes with blue-green infrastructure, usually focusing on plant-based solutions. The ecosystem services of plants offer added value to these systems. Bioretention systems are a central element of rainwater management, and pioneering research into the role of vegetation in bioretention systems has taken place in the USA and Australia. There are comparatively few publications from Europe. A systematic literature search was carried out in Web of Science using the PRISMA model. A search was made for articles that investigated the use of plants in bioretention systems in order to obtain information on practices and their use in the temperate climate of Central Europe. A strength of this review is the compilation of all species used and their reported vitality. A total of 391 taxa were described in the journals. For almost all plant species, their vitality, performance, or function in bioretention systems was only documented once. Only Carex appressa, Juncus effusus, and Panicum virgatum were examined multiple times. Of particular importance are the functional characteristics observed, which determine the survival of the plants and their ecosystem services for this application. An understanding of functional traits can be of particular assistance in selecting the right plants to optimize stormwater management.

N supply and yield of sugar beet after cover cropping: effects of cover crop species and management

Despite long-time practice, the effect of cover crop (CC) cultivation on N supply and yield of subsequent sugar beet (SB) is not clear for the temperate climate of Central Europe. To elucidate, four field trials with oil radish, spring vetch, saia oat, and winter rye CCs were conducted on typical loessial soil in Germany. Mineral fertilizer N dose was varied as second factor: zero (N0) and optimum dose (Nopt). Biomass characteristics before winter, soil mineral nitrogen content in spring (SMN), and sugar yield and total plant N content of SB were measured. The CC N effect (Neff), calculated as the difference in SB N uptake after CC minus bare fallow, was computed for the periods sowing-summer (July/August) and summer-harvest. On average, sugar yield was decreased after rye and increased after vetch CC compared to bare fallow which was more pronounced under N0 than Nopt. In the period sowing-summer, characterized by a high SB N demand, Neff was close to 0 kg N ha–1 after rye and up to +30 kg N ha–1 after vetch. In contrast, Neff in summer-harvest was negative, amounting up to –80 kg N ha–1 after radish and rye. Regression analysis revealed a significant relationship between Neff in the period sowing-summer and the sugar yield difference between the cover crop treatments and bare fallow (R2 = 0.29). A multiple regression analysis (R2 = 0.68) indicated that high CC biomass combined with a large negative spring SMN difference between CC treatment and fallow caused a large yield penalty, which can be compensated for by elevated N fertilization. Moreover, CC management ensuring either a limited CC biomass or low SMN difference of CCs compared to fallow by e.g., later sowing, less vital CC species or early CC termination, will likely secure higher SB yield after CCs than fallow.

Moisture patterns and fluxes in evolving tafoni developed in arkosic sandstone in temperate climate

AbstractCavernous weathering forms have long been studied and discussed as enigmas in geomorphology. Recently, their evolution has been shown to be controlled by moisture patterns, which are still poorly understood. For the first time, capillary water and vapor fluxes were characterized in detail at tafone in a temperate climate of central Europe using a wide range of methods adapted from soil hydrology. Time domain reflectometry showed that moisture flows from the rock interior to the evaporation front in the shallow subsurface of both — the backwalls and the outer surface. When overland flow occurs on the outer surfaces (after heavy rains), 10 mm/day can infiltrate and flow toward the backwalls. The main sources of water for tafone are the influx of water from the rock interior and the infiltration of overland flow after heavy rains, while condensation of air humidity is a minor source. Influx from the rock interior is coupled to the evaporation rate, which varies between 100 and 300 kg/m2/year in summer and less than 15 kg/m2/year in winter. More water evaporates from the backwall of the tafone than from the outer surface, and more salt is deposited in the backwalls, resulting in predominant salt weathering in the backwalls. The tafoni studied thus evolve, and the cavities deepen. Tafoni in arid and semi‐arid environments generally show a much higher contrast between evaporation rates from backwalls and outer surfaces than tafoni and honeycombs in temperate and coastal environments. Tafoni in temperate settings are therefore more susceptible to degradation when evaporation decreases or inflow to the tafone increases. This study also shows that microtensiometers can be used to determine moisture content with high spatial resolution, while time domain reflectometry allows accurate characterization of moisture patterns with depth.

Effects of supplemental oxytocin or prostaglandin F2α analogue in extended boar semen on piglet productivity of gilts and sows artificially inseminated in summer

We determined the effects of oxytocin (OT) and prostaglandin F2α analogue (PG) added to extended boar semen on the duration of artificial insemination (AI) and reproductive performance of pigs bred in July and August (temperate climate of Central Europe). Eighty gilts and second parity sows (G+SP) and sixty-four multiparous sows (M) were divided into three groups. Group OT (11 G+SP and 37 M) and group PG (20 G+SP and 28 M) were artificially inseminated twice (at the onset of estrus and 22–24 h later) using extended semen supplemented with 20 IU of OT or 5 mg of PG, respectively. Thirty-three G+SP and 15 M served as controls (C) inseminated with non-supplemented semen. The mean duration of the first AI was shorter (P<0.05) in M compared with G+SP females inseminated with PG-supplemented semen (80±22 s vs. 191±26 s, respectively), whereas the second AI was shorter (P<0.05) in M than in G+SP artificially inseminated with OT-supplemented semen (93±15 s vs. 192±28 s). The mean pregnancy rate was lower (P<0.05) in C G+SP (26/33; 85%) compared with OT G+SP females (11/11; 100%). The OT M females had more (P<0.05) stillborn piglets per litter compared with their G+SP counterparts (0.8±0.1 vs. 0.1±0.3). In summary, the addition of PG was associated with shorter first AI times in multiparous sows compared with G+SP, but with lower farrowing rates in younger animals. Oxytocin supplementation was associated with a shorter second AI and higher pregnancy rates in young females, but more stillborn piglets per litter in older sows.

Microbial diversity as an indicator of a diversified cropping system for luvisoils in a moderate climate. Case study – Long term experiments from Poland

The idea of agricultural sustainable in the EU is based on, both minimizing interference with the soil system as well as diversifying crop rotation what relates to the limited cultivation system (changed from plow to no-plowing tillage) as well as organic fertilization is often abandoned. Taking above into account, our goal was determined of the structure, composition, and metabolic profiles of soil microbiomes in various cultivation methods (under multiannual plow and no-plow cultivation) using metagenomic analysis. Having regard to the recommendations contained in EU report (European Commission et al., 2020) of the Mission board for Soil health and food, 2020 indicating the lack of microbiological indicators of “healthy soil”. So, we have tried to select of microbiological indicators showing sensitivity and resistance to use the methods of soil cultivation. The research object was located on almost 100-year field experiments at the Experimental Station of the Faculty of Agriculture and Biology in Skierniewice/near Warsaw on, luvisoils dominated in the temperate climate of Central Europe. Soil microorganisms respond with changes in their abundance and taxonomic composition depending on the methods of soil cultivation. Actinobacteria were the most abundant, while Planctomycetes were the least abundant in the metagenome of soil fertilized with manure, whereas the uncultivated soil was dominated by Nitrospirae. We can recommend the following taxa, including Gemmatimonas sp. as a microbiological indicator sensitive to the long-term lack of both plow cultivation of soil and organic fertilization, and Mycobacterium sp. as a resistancivity indicator to this soil cultivation method. Sorangium sp. could be recommended as microbiological indicators which responds by reducing the quantity under effect of the organically fertilized soil, while the plow and no-plow cultivation does not affect changes in its quantity. The use of various cultivation methods changed the biochemical functions in soil metagenoms, including nitrogen and sulfur metabolism and carbohydrate metabolism, and in the production of plant hormones and siderophores. Additionally, soil cultivation ways changed the response of microorganism’s stresses, including oxidative stress. The conducted research indicates the necessity to conduct further research on the influence of various cultivation methods, on the diversity of the microorganism community and soil metabolism. The result of which may be the selection of appropriate microbiological indicators for determining “soil health” depending on the type of soil under cultivation located in different climatic zones, not only presented in the paper.

Antioxidant and Antibacterial Activity of Helichrysum italicum (Roth) G. Don. from Central Europe.

Helichrysum italicum (Roth) G. Don. is one of the most important cosmetic and medicinal plants originating from the Mediterranean region of Europe. The aim of this study was to assess the chemical profile as well as antioxidant and antibacterial potential of the species cultivated in the temperate climate of Central Europe. The analyses were carried out using herbs and inflorescences. The content of essential oil ranged from 0.25 g × 100 g−1 in the herb to 0.31 g × 100 g−1 in the inflorescences. Neryl acetate, accompanied by α-pinene in the herb (10.42%), and nerol in inflorescences (15.73%) were the dominants here. Rutoside, as well as rosmarinic, chlorogenic, neochlorogenic, isochlorogenic b and cichoric acids, were detected in both raw materials using HPLC-DAD. Within this group, cichoric acid was the dominant (2647.90 mg × 100 g−1 in the herb, 1381.06 mg × 100 g−1 in the inflorescences). The herb appeared to be more abundant in phenolics in comparison with the inflorescences. When given antioxidant activity (determined using DPPH and ABTS assays), both methanolic extract and essential oil obtained from the herb indicated higher potential than those originating from the inflorescences (74.72, 61.38 and 63.81, 58.59% in the case of DPPH, respectively). In turn, regarding antimicrobial activity, the essential oil from inflorescences was distinguished by stronger bacteriostatic power than the herb essential oil. Gram-positive bacteria were more sensitive to both essential oils in comparison with Gram-negative ones, with S. aureus ATCC 25923 as the most susceptible (MIC 1; MBC 16 mg × mL−1) among tested strains.

How to Adapt Mongolian Yurt to the Modern Requirements and European Climate—Airtightness versus CO2 Concentration?

There are currently trends in the world to transfer and adapt traditional solutions to contemporary needs. This applies, inter alia, to mobile shelters used by nomadic peoples. The article is devoted to the research on the quality of internal air in the yurt and the possibilities of its adaptation to high contemporary quality and environmental requirements, while maintaining its characteristic sustainable values. The tested traditional Mongolian yurt was moved from the dry and cold climate of the Asian steppe to the temperate climate of Central Europe and has been significantly modified. The outer shell materials have been changed, replacing natural materials with modern tight insulating foils. The wood-fired stove has been replaced with an electric heater and the roof opening has been firmly closed. All of these modifications resulted in far-reaching changes in the quality of the internal environment in the yurt. The conducted measurements and simulations of CO2 concentration in the modified yurt proved that the efficiency of ventilation system is not sufficient and that the air quality is very poor (even for a single user). In the case of a larger number of users, the concentration of CO2 has already reached a level that was dangerous to health. The simplest method of improving the air quality in the yurt is its careful unsealing to the required level. Striving for a low energy demand, however, would require a completely different approach (for example, in the form of forced ventilation with a heat recovery unit, ultimately powered with a PV array). Such a solution is very different from the traditional yurt model but is close to modern expectations and environmental requirements.

Comparison of Single- and Multipipe Earth-to-Air Heat Exchangers in Terms of Energy Gains and Electricity Consumption: A Case Study for the Temperate Climate of Central Europe

Earth-to-air heat exchangers (EAHEs) can be used in the ventilation systems of various types of buildings. Multipipe structures can be found in large-volume buildings, yet scientific analysis of such systems is rare. Annual energy gains and electricity consumption for equivalent single-pipe and multipipe systems are typically not available. This paper bridges this gap, presenting the results of experimental studies on pressure losses in three-, five- and seven-pipe EAHEs and analysis for the annual energy gains and electric energy consumption as compared to a single-pipe exchanger. The results showed that the multipipe EAHE can be successfully replaced by a single-pipe structure with the same thermal performance and similar pressure losses if a tube with the appropriate diameter is used. However, multipipe heat exchangers can also use pipes of larger diameter (manifolds and/or branches), which improves their energy efficiency and may then make them more advantageous than single-pipe structures. From this reason, ultimately, the final selection of exchanger geometry should take into account economic and environmental issues and also user preferences and their importance in the hierarchy.

Impact of Heat Stress on Selected Parameters of Robotic Milking.

Simple SummaryThe aim of this study was to verify the effect of temperature stress on dairy cows milked in an automatic milking system in the temperate climate of central Europe. The study showed that there was not a decrease in the daily milk yield per milking if the temperature-humidity index value was lower than 68. This was accomplished with the dairy cows having an average daily milk yield of 29 kg to 31 kg. A decrease of the daily milk yield per cow was recorded if the temperature-humidity index value was greater than 72. A higher average milk speed, as well as a higher maximum milk speed, may occur with a temperature-humidity index value higher than 68.The values of the temperature-humidity index and its influence on the performance parameters of dairy cows were monitored on four farms located in the southern part of the central Slovakia during a period of three years. The observed parameters included: the milk yield per cow per day, average milk speed and maximum milk speed. The thermal-humidity index was calculated based on a formula. The individual periods were divided according to the achieved THI. The results of dairy cows with a milk yield of 29 kg to 31 kg show that there is not a decrease in the milk yield per milking if the THI value is lower than 68. It was also found that there was a decrease in the milk yield per dairy cow in the robotic milking parlor for a THI value greater than 72. The influence of a THI value higher than 68 in these dairy cows results in a higher average milk speed, as well as a higher maximum milk speed. These two parameters are not yet in the main area of research interest. This study enriches the area with new knowledge, according to which dairy cows can show thermal stress by increasing the milk speed as well as the maximum milk speed.

The Quality of Greek Oregano (O. vulgare L. Subsp. hirtum (Link) Ietswaart) and Common Oregano (O. vulgare L. Subsp. vulgare) Cultivated in the Temperate Climate of Central Europe.

The purpose of the study was to determine the differences between two subspecies: O. vulgare L. subsp. hirtum (Link) Ietswaart (Greek oregano) and O. vulgare L. subsp. vulgare (common oregano) growing in cultivation conditions within temperate climate of Central Europe. The characteristic of the subspecies was undertaken in terms of selected morphological parameters and the quality of the raw material. The herb of both subspecies was evaluated on the content and composition of essential oil by hydrodistillation followed by GC-MS and GC-FID (gas chromatography coupled with mass spectrometry and flame ionization detector), the total content of phenolic acids (according to PP 6th ed.) and the content of rosmarinic acid (by HPLC). The sensory evaluation (QDA) was performed, as well. Greek oregano was distinguished by visibly higher number of glandular trichomes on the leaves (up to 4.85 per 1 mm2) followed by higher content of essential oil in the herb (up to 3.36 g × 100 g−1 DW) in comparison to common oregano. Based on the essential oil composition, Greek oregano was classified as mixed carvacrol/γ-terpinene chemotype, while common oregano as mixed sabinyl/cymyl type rich in sesquiterpenes. Greek oregano was also characterized by higher total content of phenolic acids (up to 6.16 g × 100 g−1 DW) and rosmarinic acid (up to 6787.2 mg × 100 g−1 DW) than common oregano. Essential oil content reached the maximum at the beginning of blooming (common oregano) and at the full blooming stage (Greek oregano). In turn, the amount of phenolic acids followed by rosmarinic acid was the highest at the beginning of seed-setting stage, in the case of both subspecies. The differences between subspecies concerning chemical composition (especially essential oil) were reflected in the sensory attributes, where both odor and taste notes were found at higher level for Greek oregano. Results of our work indicate that Greek oregano is well adapted to grow in the temperate zone conditions. Such adaptation was reflected mainly in the satisfied yield and maintaining characters typical for the Mediterranean plant, e.g., a high essential oil content followed by high carvacrol share, traits the most important from practice viewpoint.

Shell morphology, growth pattern and population dynamics of the land snail Xerolenta obvia (Menke, 1828) in two areas of different climatic conditions within a temperate climate region

To determine the relative role of climatic variables (temperature and precipitation) on land snail Xerolenta obvia populations, field surveys were conducted in Poland at two sites (SW and NE) with striking differences in climatic regime during two growing seasons. In a temperate climate of Central Europe X. obvia is an annual species with the majority of snails hatching in autumn. They overwinter as juveniles, continue their growth in spring and summer, and reproduce in the following autumn. Due to the comparatively milder climate, the SW population is more plastic, some individuals can live and reproduce longer. The two variants of the growth model are presented. We found that the length of growing season and temperature were additional factors determining differences in snails’ growth and population dynamics between the sites. The growth rate of X. obvia is negatively correlated with the initial size of their shells and varies among sites. These two geographically distant populations differ in terms of their shell size and morphology. The SW population is characterised by larger, dark banded shells compared to the NE one, which is dominated by snails with smaller, white shells. A pattern of decreasing body size in areas with shorter growing season may explain differences in the shell size of X. obvia. Larger shells in regions with warmer and drier environment perhaps constitute responses to selection by environmental factors.

Comparison of the energy efficiency of methane and ethanol production from sweet sorghum (Sorghum bicolor (L.) Moench) with a variety of feedstock management technologies

This study investigated the energy outputs from methane and ethanol production from sweet sorghum (Sorghum bicolor (L.) Moench). Different methods of sorghum biomass management were compared. The effect of bio-based waste products – sewage sludge and digestate replacing urea – on the energy output of biofuels produced from two different hybrids of sweet sorghum was evaluated. Conversion of fresh sorghum biomass into methane generated 76.6–179.5 GJ ha−1, while the gross energy output from ethanol was only 22.6–70.5 GJ ha−1. Application of digestate allowed the highest energy efficiency ratio to be obtained in terms of ethanol production for both tested hybrids and in terms of methane for Rona 1. Sorghum should be used as biogas feedstock in the temperate climate of Central Europe. The application of waste – sewage sludge and digestate – in feedstock management increased the energy efficiency of biofuel production.

The Thermoregulatory Behavior of Nectar Foraging Polistine Wasps (Polistes dominula and Polistes gallicus) in Different Climate Conditions.

Polistine wasps collect nectar for their energetic demand and for the provision of the brood. They are mainly ectothermic during different behavioral tasks. We investigated the body temperature of two species living in differing habitats and climate regions, in order to reveal the environmental influence on their thermoregulatory behavior. The species were Polistes dominula in the temperate climate of Central Europe, and Polistes gallicus in the warm Mediterranean climate of Southern Europe. The wasp’s body temperature was measured during foraging on lovage (Levisticum officinale) and fennel (Foeniculum vulgare) by infrared thermography in the entire ambient temperature range they are usually exposed to (Ta ~ 20–40 °C). The temperature of all body parts increased nearly linearly with ambient temperature, with the thorax as the warmest part. To achieve optimal foraging temperatures, they preferably use solar radiation. An “operative temperature model” enabled the evaluation of the endothermic effort. Polistes dominula foraging on lovage exhibited no endothermic activity. However, while foraging on fennel they had a weak and almost constant endothermic performance of about 1 °C. Polistes gallicus, by contrast, exhibited mostly no or only minor endothermy during foraging. Both wasps avoid a high energetic effort and this way reduce their foraging costs.

Yield and seed composition of 10 spring camelina genotypes cultivated in the temperate climate of Central Europe

Camelina (Camelina sativa (L.) Crantz) is an oilseed crop of the family Brassicaceae. In the past, camelina was used mainly in food production. However, the species also has numerous industrial applications. The aim of this study was to determine the agronomic performance (seed, straw and oil yield) and the qualitative parameters (oil and protein content, fatty acid composition) of 10 spring camelina genotypes. The experiment was conducted from 2015 to 2018 in north-eastern Poland. The phenological phases, seed and biomass yield, and the composition of spring camelina seeds, including oil and protein content and fatty acid composition, were determined. The cumulative growing degree days from sowing to maturity for all genotypes were determined at 1200 °C d. Seed yield ranged from 1.70 Mg ha−1 dry matter (d.m.) in genotype 787-15 to 2.21 Mg ha−1 d.m. in genotype 887. Seed oil content was determined at 39.3–42.2% d.m. Oil yield was high in genotype 787-15 (0.93 Mg ha−1) and low in genotype 887 (0.69 Mg ha−1). Three main genotype groups were identified during the study. The first group was characterized by a high content of monounsaturated fatty acids (MUFAs) and a low content of polyunsaturated fatty acids (PUFAs). These genotypes were abundant in linolenic acid. The second group was composed of genotypes with a high content of PUFAs and a low content of MUFAs and saturated fatty acids (SFAs). These genotypes were characterized by high oil yields and a high content of linoleic acid. The third group was characterized by a high content of SFAs, a high content of PUFAs and a low content of MUFAs. The tested spring camelina genotypes had a high yield potential (in particular genotypes 787-15, 787-08 and 787-05) and were good candidates for commercial cultivation in the temperate climate of Central Europe. Genotype 887 cannot be recommended for cultivation due to its low seed yield, low oil content and low oil yield.

Vertisols properties and classification in relation to parent material differentiation near Strzelin (SW Poland)

Abstract Vertisols are characterized by high content of clay fraction that affects their specific morphological and physical features. The shrink-swell phenomena of clayey materials under specific moisture regime cause formation of cracks, wedge-shaped structural aggregates and slickensides on aggregate surfaces. It was formerly believed that these soils can be found only in tropical/subtropical zones, thus Vertisols have not been expected to form under temperate climate of Central Europe. As a result, Vertisols are insufficiently recognized and documented on soil maps in Poland, including the Lower Silesia region. The aim of this study was to examine soils developed on clayey parent materials near Strzelin, focusing on their morphology, properties and classification issues. There was confirmed that soils developed from Neogene clays have vertic and mollic horizon, accompanied by stagnic or gleyic properties. However, not all soils fulfil the criteria for Vertisols due to the presence of surface or subsurface coarser-textured (sandyor silty-textured) layers. Native differentiation of parent material and geomorphological processes were found the main factors, which control the spatial mosaic of Vertisols and black earths (Chernozems or Phaeozems).

The Effect of Potassium and Sulfur Fertilization on Seed Quality of Faba Bean (Vicia faba L.)

Faba bean seeds are regarded as a highly valuable protein source for human and animal nutrition. High yield and quality of faba bean require adequate mineral nutrition. The aim of the study was to assess the impact of potassium (K) and elemental sulfur (S) on crude protein (CP) and tannin content (TC) in seeds, crude protein yield (CPY), and amino acid (AA) composition. Field trials were carried out during 2010–2013 in the temperate climate of Central Europe. The study assessed the influence of the following factors: variable soil K content and fertilization (K1, K2, K3, and K4) and elemental S application (0, 25, and 50 kg S ha−1). Plants were harvested at two growth stages to obtain immature seeds and mature seeds. K and S applications did not have a significant impact on CP and AA composition, including sulfur AA content. The TC decreased in response to increasing content of plant-available K in soil. In respect to CPY, the results indicate a positive response of faba bean to increasing K content in soil. The effect of S fertilization depended on the K treatment. The most beneficial influence of S on CPY was registered on K-poor soil.

Promoting the Use of Common Oat Genetic Resources through Diversity Analysis and Core Collection Construction.

The assessment of diversity and population structure and construction of a core collection is beneficial for the efficient use and management of germplasm. A unique collection of common oat landraces, cultivated in the temperate climate of central Europe until the end of the twentieth century, is preserved in the Polish gene bank. It consists of 91 accessions that have never been used in breeding programs. In order to optimise the use of this genetic resource, we aimed to: (1) determine genetic and agro-morphological diversity, (2) identify internal genetic variation of the tested accessions, (3) form a core collection and (4) recognise the accessions useful for breeding programs or re-release for cultivation. The collection was screened using ISSR markers (1520 loci) and eight agro-morphological traits. Uniquely, we performed molecular studies based on 24 individuals of every accession instead of bulk samples. Therefore, assessment of the degree of diversity within each population and the identification of overlapping gene pools were possible. The observed internal diversity (Nei unbiased coefficient) was in the range of 0.17–0.31. Based on combined genetic and agro-morphological data, we established the core collection composed of 21 landraces. Due to valuable compositions of important traits, some accessions were also identified as useful for breeding programs. The population structure and principal coordinate analysis revealed two major clusters. Based on the previous results, the accessions classified within the smaller one were identified as obsolete varieties instead of landraces. Our results show that the oat landraces are, in general, resistant to local races of diseases, well adapted to local conditions and, in some cases, yielding at the level of modern varieties. Therefore, in situ conservation of the landraces in the near future may be satisfactory for both farmers and researchers in terms of the genetic resources preservation.

Pure sowings versus mixtures of winter cereal species as an effective option for fodder–grain production in temperate zone

In a three-year field experiment carried out from 2006–2009 in the temperate climate of Central Europe, the growth and yield of four species of winter cereals, namely, barley, rye, wheat and triticale and their four mixtures (barley+rye and wheat+triticale; each mixture of two shares: 67%+33% and 50%+50%), were compared. Mixed sowings proved to be an effective agro-technological option for a sustainable agriculture in the region. Mixed sowings of winter cereals yielded approximately 0.94Mgha−1 more, as compared to pure sowings, especially in the cooler and wetter growing seasons. In each of the mixtures, height convergence occurred, specifically a shortening of the long-culmed cereal species and an increase in the length of the short-culmed species. It resulted in improved resistance of the canopy to lodging, and an increase in the production of feed grain, in comparison to cereals in the pure sowings.Such a system of interactions between cereals in mixtures resulted in a land equivalent ratio of >1. The length and productivity of the inflorescences and also the harvest index were mostly species-specific. A 50:50 share of species was more effective for the rye and barley mixture, whereas 67:33 was better for the mixture of wheat and triticale. In the mixture, rye showed increased competitiveness as compared to barley.

Lighting characteristics during the polar day and their impact on changes in melatonin secretion

People traveling between climate zones can be exposed to extreme environmental stimuli which significantly differ from their place of habitual residence. A move from the temperate climate of Central Europe to the subpolar climate of northern Europe means exposure to great changes in two climate parameters: lighting and biothermal characteristics. The sudden change of solar radiation, temperature, wind and humidity, force the organism to undergo intensive adaptation processes. While the change in lighting conditions involves a diurnal rhythm adaptation of the physiological clock (regulated by the hormone melatonin), the change of biothermal factors (represented by UTCI) produce additional stress on the strongly loaded human organism. The field experiment was carried out in Poland and Norway so the impact of the selected radiation stimuli on melatonin production could be carried out in conditions of natural constant lighting. The paper presents the results of the preliminary analysis of our research conducted from 22 May to 12 June 2011. The distribution of daily outdoor photosynthetically active radiation (PAR) intensity, which is a spectral distribution of solar visible radiation in selected times of the day were analyzed. Lighting conditions surrounding each subject (doses of reached energy of visible solar radiation and illumination intensity) were examined as well. Additional adaptation stress caused by different biothermal conditions (expressed by UTCI index) was also taken into consideration. Diurnal melatonin concentrations were determined in saliva samples.

Effect of sowing date and variety on yield and weed populations in a lentil–barley mixture

SUMMARYThe present study examined variation in sowing date on lentils (Lens culinaris) in a standard lentil–barley (Hordeum vulgare) mixed cropping system in the temperate climate of central Europe to determine the effect on crop yield and weed control. A 2-year (2009/10) field experiment was carried out at the organic research station Kleinhohenheim (KH) and at the conventional research station Oberer Lindenhof (OLI) of the University Hohenheim, southwest Germany. The crop was sown at three dates in the period from March to May. Grain yield was significantly higher at the earliest sowing both for lentils (3·0 t/ha at KH, 2·4 t/ha at OLI) and barley (1·2 t/ha at KH, 2·6 t/ha at OLI). Weed biomass at KH increased significantly with delayed sowing and was independent of lentil genotype, whereas sowing date had no significant effect on overall weed biomass production at OLI. Unlike weed biomass, weed density generally decreased significantly with delayed sowing at OLI. The results indicate that early sowing can increase the yield of lentils, and can be used as an indirect method of weed control in some organic farming systems.