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Celem pracy była ocena efektywności energetycznej dwupolowych członów zmianowania ugór – pszenica ozima. Ocenę przeprowadzono w oparciu o wyniki doświadczenia polowego zrealizowanego w latach 2003-2006 w Zakładzie Doświadczalno-Produkcyjnym Bałcyny, należącym do Uniwersytetu Warmińsko-Mazurskiego. Przedplonem dla pszenicy ozimej były: ugór czarny, ugór herbicydowy i trzy warianty ugoru zielonego z gorczycą białą, koniczyną perską i życicą westerwoldzką. Stwierdzono, że najwyższe nakłady energetyczne poniesiono na utrzymanie ugoru czarnego, a najniższe – ugoru herbicydowego. Z porównywanych dwupolowych członów zmianowania najwyższym wskaźnikiem efektywności energetycznej (8,2) charakteryzował się układ: koniczyna perska – pszenica ozima, przy jednocześnie najmniejszych nakładach energii na produkcję 1 jednostki zbożowej (JZ). Najniższy wskaźnik efektywności energetycznej (5,4) zanotowano w członie zmianowania: życica westerwoldzka – pszenica ozima.
During exclusion of the land from market production for two vegetation seasons the highest energy outlays were incurred for maintaining the black fallow and the lowest for the herbicide fallow. In winter wheat production technique the highest energy outlays (15 800 MJ ha⁻¹) were incurred in materials. In the group of outlays for materials, 66.4% were fertilizers, 31.4% the sowing material and just 2.2% the plants protection media. The second largest flow of energy outlays consisted of energy carriers at 1754.1 MJ ha⁻¹, among which the largest shares were those of soil cultivation 54.3%, harvest 17.9% and crops cultivation 13.2%. Tractors and machines were the third largest energy consumers group (731.1 MJ ha⁻¹), where the demand structure was as follows: 35.5% harvest, 34.5% soil cultivation and 15% crops cultivation, fertilization 9.2% and sowing 5.8%. Among the agricultural technique components, fertilization and sowing had the largest share representing respectively 58.0% and 27.8% of all outlays. Among the compared three-field rotation system components, the highest energy efficiency coefficient of 9.9 was achieved while cultivating winter wheat after two-years of red clover, which was coupled with the lowest energy outlays for production of 1 cereal unit. The lowest energy efficiency coefficient (5.4) was achieved in the crops rotation system component of black fallow – black fallow – winter wheat.
Trans-4-hydroxy-2-nonenal (4-HNE), a cytotoxic end product of lipid peroxidation, is present in normal human blood plasma at concentrations of 0.1-1.0 μM. It can be, however, further metabolized within a cell, and one of the main products is 4-HNE glutathione conjugate (HNE-SG). In human erythrocyte membrane the system for active extrusion of glutathione (GSH) conjugates of various endo- and xenobiotics has been described; it exhibits either a low (Km at submillimolar concentration range) or a high (Km at low micromolar range) affinity for the transported substrates, such as for example S-(2,4-dinitrophenyl)glutathione (Dnp-SG). In the present study it has been shown that the high affinity transport system for Dnp-SG is competitively inhibited by HNE-SG with Ki of 0.2 μM, while 4-HNE inhibits non-competitively the activity of the transport system for Dnp-SG with Ki of 220 μM. These observations point to the possibility that HNE-SG shares the same transport system with GSH conjugates of other endo- and xenobiotics in erythrocytes. This may be of importance for overall detoxification of the organism under oxidative stress.
During the growth of underplant and cover crop interactions occur, the patterns and mechanisms of which are not totally known, particularly within the changeability of ecological factors. Joint use of environmental resources may modify the uptake of nutrients from the bedding and their accumulation in the particular plant organs. The aim of the study was the determination of the effect of interactions between spring barley and red clover on phosphorus content in their organs against diversified water provision. In a pot experiment (three cycles), the study factors were: (1) plant sowing type (growth of each species in pure and mixed sowing), and (2) plant provision with water (dose that satisfies plant requirements and one lowered by 50%). Mixture was composed according to the additive pattern. Phosphorus content was marked in plant material uptaken at five stages set by the developmental rhythm of barley in pure sowing in the conditions of more favourable water supply. Sowing type had no effect on phosphorus content in spring barley organs but mixed sowing resulted in the accumulation of a higher amount of phosphorus in the roots at the straw-shooting stage, and a lower amount in the shoots and spikes at the end of growth. In red clover, mixed sowing lowered phosphorus content in the roots at cereal maturity stage. Competition on the part of barley inhibited the uptake and accumulation of phosphorus by red clover. Water supply did not diversify phosphorus content in the organs of spring barley and red clover but water deficit almost throughout the entire period of growth limited phosphorus uptake by both species. Competition on the part of barley was for red clover a stronger factor that impeded phosphorus accumulation in plant organs than water deficit. Water stress did not intensify further the negative effect of competition.
The effects of phosphorus biofertilizers made from animal bones and sewage sludge ash and containing phosphate-solubilizing bacteria, Bacillus megaterium, were analyzed in a field experiment involving spring wheat. It was assumed that biofertilizers would be as effective as conventional phosphorus fertilizers such as superphosphate and phosphorite. The influence of biofertilizers on the growth rate of Bacillus megaterium bacteria in soil, the total counts of heterotrophic bacteria and fungi, the abundance of earthworms, and soil moisture and temperature were analyzed. Phosphorus biofertilizers containing ash and bones did not increase the abundance of Bacillus megaterium in soil, but unlike superphosphate they stabilized the strain’s population in the soil environment. The tested phosphate fertilizers and biofertilizers did not influence the total counts of heterotrophic bacteria and fungi in soil, the abundance of earthworms, soil moisture, or temperature.
On the basis of a pot experiment set up according to the additive design, the effect of competitive actions of spring barley on the morphological characteristics of red clover in the conditions of water stress was evaluated. Biometric analyses were carried out on five dates set by the growth rhythm of barley in pure sowing with a higher water dose. The study included: plant height, number of shoots and leaves per plant, and root length. On the basis of plant biomass, relative yield, relative yield total, and competitive balance index were determined. It was demonstrated that spring barley, from tillering to the end of growth, limited red clover plant height and root length. At the straw-shooting stage, negative effect of the cereal intensified and caused the formation of a smaller number of leaves and shoots than in clover in pure sowing. Water shortage caused plant shortening (from barley tillering to the end of growth) and reduction in the number of leaves (tillering – earing) and shoots (straw-shooting and ripening) of clover.
Based on a 3-year pot experiment carried out according to an additive design, the effect of competitive effect of red clover and water deficit was studied on morphological traits of spring barley (length of the root, shoot and ear, total and productive tillering, leaf number and grain number per ear). The experimental factors included: level of substrate moisture and sowing method. Two levels of moisture were used: the one which met plants’ requirements, and one reduced by 50%. The plants were sown in a pure stand (18 plants of spring barley per pot) and in a mixed stand (18 plants of spring barley with 8 plants of red clover per pot). Biometric measurements were conducted in five development stages determined by the growth rhythm of barley in pure sowing with a higher water dose, i.e. in the stages of (BBCH scale): leaf formation (10-13), tillering (22-25), shooting (33-37), ear formation (52-55) and maturation (87-91). It was indicated that common cultivation of spring barley with red clover had no effect on the analyzed morphological traits of this cereal throughout the whole growing season. On the other hand, water deficit in the substrate resulted in a reduction in cereal growth in tillering-maturation stages, in the formation of a lower number of leaves (tillering-shooting) and in a poorer total and productive tillering. Water stress also caused formation of shorter ears with a lower number of grains filling them. Competitive effect of red clover amplified with water deficit resulted in the reduction in the number of productive shoots in barley. No effect of experimental factors was found on the root length in the initial growth stages (leaf formation-tillering).
A pot experiment was conducted in a greenhouse in Olsztyn, Poland, in the period 2010–2012. The aim of the study was to examine whether soil water deficit would change biomass volume and distribution of pure sown spring barley and red clover as well as growth rate during their joint vegetation and mutual interactions. The interactions between spring barley and red clover were of a competitive character, and the cereal was the stronger crop. The strength of this competition increased in time with the growing season. Through most of the growing season, the competition was poorer in water deficit conditions. The impact of clover on barley before the heading stage showed facilitation symptoms. Interspecific competition reduced the rate of barley biomass accumulation and decreased stem and leaf biomass towards the end of the growing season. Intensified translocation of assimilates from the vegetative parts to grain minimized the decrease in spike biomass. Water deficit stress had a more inhibitory effect on the biomass and growth rate of barley than competition, and competition did not exacerbate the adverse influence of water deficit stress on barley. Competition from barley significantly reduced the biomass and biomass accumulation rate of clover. Water deficit stress did not exacerbate barley’s competitive effect on clover, but it strongly inhibited the growth of aboveground biomass in pure-sown clover.
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