•New conceptual model for development of the soil magnetic signal is proposed.•Accretional soils show parallel variations in magnetic grain size proxies with soil depth.•Soils developed without dust ...input show shifts in the depth of maximum enhancement.•Temperature plays role for the coarser grain size of the pedogenic fraction in accretional soils.
Magnetic properties of loess-paleosol sequences are widely utilized as sensitive, easily-obtained and reliable proxy archives of past climate change in continental settings. However, soil formation in aeolian landscapes may occur under different and changing conditions of dust sedimentation, which will affect the growth and development of the pedogenic magnetic component. This phenomenon is explored in our study by analyzing depth variations of the following magnetic characteristics: frequency dependent magnetic susceptibility, anhysteretic magnetic susceptibility and the ratio between anhysteretic susceptibility and isothermal remanent magnetization acquired in a 100 mT back field (χarm/IRM-100 mT), along three loess-paleosol profiles from NE Bulgaria. A conceptual model for the time evolution of the grain size of the pedogenic magnetic fraction with soil depth is proposed, which is build upon the mechanism of soil formation – accretional or in stable land surfaces, or a combination of the two. Another magnetic ratio – isothermal remanence acquired in a 300 mT back field divided by low field magnetic susceptibility (IRM-300 mT/χ) is utilized as a proxy for the changes in the ratio of silt to clay fractions, indicative of changes in dust sedimentation regimes during glacial-interglacial transitions. According to the proposed conceptual model, verified by the magnetic signature of three Holocene soils from NE Bulgaria, discrimination between accretional soils and soils developed without dust additions during soil forming period can be done. Accretional soils are characterized by parallel changes in grain size sensitive magnetic proxies. Soils, developed at stable landscape conditions show gradation of the depths at which maximum enhancement of various proxies occurs with deepest occurrence of the maximum in χfd, followed by depth of maximum χarm and χarm/IRM-100 mT. Another implication of the new conceptual model is that the mean coercivity of the pedogenic component of accretional soils will be higher than that of soils developed without eolian input at equal temperature conditions because of the soils' thermal gradient and different depths, at which pedogenic minerals form in the two settings. The results revealed that the Holocene soils (So) has developed under different soil-forming conditions than paleosols from the same sites.
The Golden and Fibonacci geometry forms are symbols of beauty and harmony. The shapes and symbols in the national traditions are always a source of creative ideas. The paper presents textile designs ...on the base of creations from the Golden and Fibonacci geometry and Bulgarian national tradition. Fourteen textile design project are presented with the use of the Golden spiral in the Golden square, Fibonacci series tiling with equalitarian triangles named Fibonacci rose and the spiral square with four Golden spirals from the Golden and Fibonacci geometry, and the three turtles – symbols from Kolobar tradition in Bulgarian national culture. The forms from the Golden and Fibonacci geometry are used directly as ornaments, constructional elements for ornaments, or as frames for entered elements. The symbols from Kolobar tradition are used directly as ornaments. Every design is presented in suitable two, three or four color model. The used geometrical forms from the Golden geometry and the Bulgarian national tradition are the base for successful textile design using the mirror, radial and translated symmetry and the plain rhythms as result from their combinations. The design is more successful when the geometrical ornaments are combined with suitable colors according to the connections between colors and lines on the base of their meaning, the latest fashion trends, and national traditions.
Despite the fact that successive sowing of maize was legally limited due to the occurrence of the corn rootworm beetle in 2003 and the integrated crop production was introduced in 2004, maize is ...still the most common and desired crop on arable and livestock farms in Slovenia. With a focus on the economic motives for the production farmers are gradually beginning to consider also the phytosanitary viewpoint, but the planning of a crop rotation is a demanding task, especially for younger farmers with no previous experience. The results of the analysis of crop rotations on conventional and integrated arable and livestock farms in north-east and western Slovenia in the period from 2000 to 2009 show that the maize monoculture has been supplemented by other grains, mostly wheat and barley, but legumes and supplementary crops are still missing from the rotation. With newly introduced crops to Slovene fields the need for new and modern agro-technical measures is increasing and also the need for improved knowledge of biological characteristics of individual varieties and species with their suitable order and share in the crop rotation. To help the farmers find the best solution for their production we have prepared some recommendations for the crop rotations with the main and supplementary crops, following good and proven examples of crop rotations used in the past. Whether farmers will use them on their farms depends not only on their technical equipment and knowledge, flexibility and receptiveness, but also on the legislative measures and sustainable nature of EU agricultural policy where farmers got used to be paid for every function and production that is environmentally and food friendly.
V Sloveniji je koruza, kljub zakonski omejitvi zaporedne setve zaradi pojava koruznega hrošča leta 2003 in vključevanja kmetij v integrirano pridelavo poljščin leta 2004, še vedno najbolj razširjena in zaželena poljščina na poljedelsko-živinorejskih kmetijah. Ekonomski vidik pridelave postopoma upošteva fitosanitarnega. Načrtovanje kolobarja je zahtevno, zlasti za mlajše kmete, ki nimajo izkušenj iz preteklosti. Rezultati analize kolobarjev na konvencionalnih in integriranih poljedelsko-živinorejskih kmetijah v severovzhodni in v zahodni Sloveniji v obdobju od leta 2000 do 2009 kažejo, da so monokulturo koruze razbremenila druga žita, zlasti pšenica in ječmen, manjkajo pa stročnice in dosevki. Z novo vključenimi poljščinami se povečujejo potrebe ne le po novi in sodobni agrotehniki, ampak tudi po poznavanju bioloških zakonitosti posameznih vrst in sort ob hkratni primerni razporeditvi in deležu v kolobarju. V oporo kmetom smo sestavili nekaj biološko uravnoteženih kolobarjev iz glavnih posevkov in dosevkov, ki se zgledujejo po preizkušenih vrstilnih kolobarjih iz preteklosti. Njihova uporaba na kmetijah bo odvisna ne le od tehnične opremljenosti kmetije, znanja, dojemljivosti in prožnosti gospodarjev ampak v glavnem od zakonskih predpisov in sonaravnih usmeritev kmetijske politike v EU, kjer so se kmetje navadili na plačilo za vsako okolju in hrani prijaznejše opravilo in postopek pridelave.
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