—
Soil formation on the human time scale is immensely time consuming, although it can be significantly accelerated through the effects of vegetation. The content of water-stable aggregates (WSAs) is ...a useful indicator for determining both the soil development level and the soil quality. However, in severely degraded soils, especially in the Baltic pedoclimatic region, the effects of vegetation on the aggregate stability have been poorly studied. Therefore, to obtain more knowledge about the impact of vegetation on WSA, and thereby knowing how to improve it, this study was conducted on a long-term soil formation experiment in Estonia near Tartu. In 1964, the initial soil from an area of 20 × 8 m down to 100 cm depth was replaced with a sandy loam calcareous glacial till. The experiment started on April 26, 1965, when plants were sown on the plot. The topsoil (0–20 cm) samples were analyzed in 1966, 2000, 2007, and 2014. The study indicated that perennial grasses (meadow fescue and common meadow-grass) fertilized with P
40
K
75
, compared to N
150
P
40
K
75
, decreased the WSA content, as well at the accumulation rate of soil organic carbon (SOC) and the total nitrogen content (N
tot
). The hybrid alfalfa treatment resulted in the significantly highest SOC and N
tot
accumulation, but not in the overall highest WSA content. Under barley, manure positively affected the WSA and SOC, though many other physical properties were not improved. Compared to the initial till under bare fallow, the SOC and N
tot
contents were significantly higher under grown crops, but the WSA content remained the same. In addition, regardless of the grown crops, the WSA of larger (0.25–2 mm) aggregates was substantially higher than that of smaller (0.25–1 mm) aggregates. Also, as the relationship between WSA and SOC in the study was linear, the soil was far from C saturation and still in development. Overall, it can be concluded that the cultivation of perennial grasses and hybrid alfalfa on the severely eroded soil is the most rational option to improve the water stability of aggregates and increase the SOC and N
tot
contents. However, because of the complexity of the aggregation process, further research is still needed.
The scientific borehole Baden-Sooss penetrates a succession of Badenian (Langhian, Middle Miocene) sediments at the type locality of the Badenian, the old brickyard Baden-Sooss in the Vienna Basin. ...The sedimentary succession of the 102-m-cored interval consists of more than 95% bioturbated, medium-to-dark gray marly shales with carbonate contents between 11 and 25% and organic carbon contents between 0.35 and 0.65%. Biostratigraphic investigations on foraminifera (mainly lower part of Upper Lagenid Zone) and calcareous nannoplankton (standard zone NN5) indicate an early Badenian (Langhian) age. Cycles in carbonate content, organic carbon content, and magnetic susceptibility have been identified by power spectra analysis. Correlations between the three variables are extremely significant. Using cross-correlation, periods around 40 m correlate significantly with the 100 kyr
−1
eccentricity cycle, the ∼20 m periods with the obliquity cycle, and the 15 to 11-m periods with both precession cycles. Wavelet transformation and decomposition of composite periodic functions were used to obtain the position of the cycle peaks in the profile. Cross-correlation with orbital cycles (La2004) dates the Baden-Sooss core between −14.379 ± 1 and −14.142 my ± 9 kyr.
El choque térmico y la pre-brotación temprana incrementa el desarrollo inicial de plantas de patata (Solanum tuberosum L.), lo que permite una recolección más temprana. El cultivo de patatas ...tempranas sin pre-brotación no es económicamente viable en las condiciones climáticas de los países nórdicos. El objetivo de este estudio fue determinar qué tratamiento de presiembra de tubérculos para semilla (sin tratar, choque térmico y pre-brotación) influyen en el tiempo de emergencia, el peso medio del tubérculo, el número de tubérculos por planta, y el rendimiento, incluyendo la dinámica del mismo. Se encontró que el choque térmico de los tubérculos acortó el tiempo de emergencia en 2-5 días y la pre-brotación entre 7-12 días. Además, el choque térmico incrementó el número de tubérculos, aunque su peso fue menor que los tubérculos producidos mediante pre-brotación. Un rendimiento muy temprano es posible con tamaño grande de tubérculo aplicando pre-brotación, siendo el periodo de recolección de tubérculos tratados con choque térmico algo posterior. Los tubérculos sin tratar fueron los que mostraron una menor producción.
Thermal shock and pre-sprouting increase the initial development of potato (Solanum tuberosum L.) plants, allowing for earlier harvests. Growing early potatoes without pre-sprouting is not economically viable under Nordic climatic conditions. The aim of this research was to determine how seed tuber pre-planting treatments (untreated, thermal shock and pre-sprouting) influence time to emergence, mean tuber weight, the number of tubers per plant, and yield (including yield dynamics). The main findings of this work were that thermal shock shortened the time to emergence by 2-5 days, while pre-sprouting shortened it by 7-12 days. In addition, thermal shock significantly increased the number of tubers produced, although their mean weight was lower than that of the tubers produced by the pre-sprouted plants. The presprouted tubers provided a very early harvest of large tubers; the harvest time for the thermal shock-treated tubers was a little later. The untreated seed tubers were the last to produce harvestable plants.
The productivity of sown pasture swards and herbage intake by dairy cows Selge, A. (Estonian Agricultural Univ., Tartu (Estonia). Dept. of Grassland Husbandry and Botanics)
Proceedings of M.Sc. and Ph.D. candidates of Estonian Agricultural University (Estonia),
(1993), Volume:
1
Publication
The present paper deals with the results of field experiments (established on the pseudopodzolic soil), conducted in 1998-1991. At the establishment of a pasture the seed mixture included 3 kg/ha of ...white clover. Comparing the productivity of different varieties of white clover, the highest yield of dry matter was obtained from the sward abundant in "Jogeva 4" and "Tooma" (Estonian native varieties). The variety "Tooma" bred for cultivation on the peat soils gave good yield also on the mineral soil. Differences in the intake of white clover rich grassland herbage were caused by the different rate of white clover in the yield of grass, but not by the various varieties of white clover. The grass sward included four different dominated grass species: cocksfoot (Dactylis glomerata cv. Jogeva 220), foxtail (Alopecurus pratensis cv. Haljas), ryegrass (Lolium perenne cv. Valinge) and tall fescue (Festuca arundinacea cv. Zapadnaja). Grazing should be practiced to keep the best possible balance between growth and intake of grass
The productivity and nutritive value of grass-legume mixtures Laidna, T. (Estonian Agricultural Univ., Tartu (Estonia). Inst. of Grassland Science and Botany); Lillak, R; Loid, H ...
Transactions of Estonian Agricultural University (Estonia),
(1994)
178
Publication
It is one of the main dilemmas in grassland husbandry: which source of nitrogen should be preferred- whether N of fertilizers (growing of grasses) or symbiotically fixed one (legumes sown pure or in ...a mixture with grasses). The present paper deals with an influence of different leguminous herbage species and cultivars on the production of dry matter and crude protein by grass-legume mixtures and on the chemical composition of dry matter as compared with the grasses sown pure and applied by different annual rates of mineral nitrogen. The paper summarizes the results of 13 experimental years: in 1979...1991 five field trials on Pseudopodzolic soils at Eerika Agronomical Experimental Station were carried out. On soils with a favourable water regime, it is recommended to enlarge the acreage under fodder galega, because it is a protein-rich forage crop, which has a good persistency and a relatively stable seed yield. Galega may be sown both in pure sowing and in mixtures with tall grasses. A complete replacement of bastard and yellow lucerne by fodder galega in Estonia is not justified. Lucerne, as a drought-resistant protein-rich crop, should be cultivated on the Rendzina of North Estonia and islands, and on the calcareous soils of moraine hills in South-East Estonia
► We investigated public and scientific understandings of fundamental concepts in invasion biology. ► Species’ perceived harmfulness and human responsibility for their spread were the most important ...arguments in the debate. ► The concept of non-nativeness was less important and understood heterogeneously. ► More transparent communication of such fundamental concepts may improve policy and conservation efforts.
The potential of invasive non-native species to modify ecosystems is well established. Yet, the resulting visibility of the field of invasion biology and its growing influence on policy decisions has led to the development of persistent critique. In addition, public opposition to the removal of non-native species has repeatedly delayed interventions, sometimes to the point where eradication has become impossible. Understanding the views of the lay-public is thus of crucial importance. Our study investigated views on invasive non-native species as held by both the general public and ecologists. We chose an in-depth qualitative social scientific approach to identify species attributes that people draw on to evaluate biological invasions and potential management options. Interviews and focus group discussions (n=79 participants) were conducted in the North-east of Scotland, and included members of the public from a wide range of backgrounds, as well as research ecologists and professionals dealing with invasive non-native species. Two key arguments, namely (i) harmfulness of a species and (ii) human responsibility for its spread, shaped both ecologists’ and lay-people’s discussions. Non-nativeness was understood by our participants in various ways and did not necessarily raise concerns about a species. Our results indicate that for information campaigns on species management to be effective, values inherent to the debate about invasive non-native species need addressing in a more explicit and transparent manner. Arguments such as human responsibility that are currently neglected in the scientific discourse, but that were important criteria for a wide range of participants, should be made explicit.
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