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W pracy omówiono wyniki 3-letnich badań nad zbiorowiskami chwastów w łanie rzepaku ozimego uprawianego w 6-polowym płodozmianie po grochu oraz 26-28-letniej monokulturze, nie traktowanego i traktowanego herbicydami. W płodozmianie bez ochrony herbicydami stwierdzono 246 osobników chwastów na 1 m2 o łącznej masie 107 g, a na obiekcie z herbicydami odpowiednio 84 i 47. Dominantami byly: Capsella bursa-pastorís (L.) Medicus, Matricaria discoidea DG. i Stellaria media (L.) Viii. W uprawie ciągłej bez stosowania herbicydów zbiorowisko chwastów liczyło średnio 811 osobników o masie 523 g, a po ich zastosowaniu wartości te zmalały odpowiednio do 144 i 185. Dominowały Stellaria media (L.) Vill., Matricaria discoidea DG. i M.perforata (L.) Schultz-Bip. W warunkach braku ochrony w biomasie łanu przed zbiorem rzepaku udział chwastów wyniósł w płodozmianie - 9%, a w monokulturze - 48%; z ochroną chemiczną odpowiednio 5 i 16%. W płodozmianie rzepak ozimy nie chroniony chemicznie plonował na poziomie 4.58 t nasion, podczas gdy chroniony dal plon o 13% mniejszy. W wyniku silnej konkurencji chwastów w monokulturze bez stosowania herbicydów uzyskano tylko 1,94 t nasion. Dzięki ochronie rzepaku herbicydami zwiększono go o 80%.
The article evaluates the land use structure in municipalities of the Warmian-Masurian voivodeship (Poland) in 2002–2012. The dynamics of changes in land use and the correlations between the components of the agricultural environment and land use structure were determined.The trends in land use and agricultural land management were identified, and agricultural and forest ecosystems were evaluated. Clusters of municipalities characterized by similar habitat conditions and land use were identified. The land use structure in the analyzed region was highly stable, and it was strongly correlated with the natural environment. A minor decrease in the percentage share of arableland, grassland and orchards was noted, and it was accompanied by an increase in forest cover in all municipalities. The forest cover in Warmia and Mazury exceeds the level planned for 2020. The applied classification methods produce highly similar results, and they point to clear regional variations in the natural and agricultural environment. The northern part of the region comprisesmostly agricultural land, and it ranks lower with regard to its ecological importance. Agricultural acreage is also the predominant type of land use in the south-western part of the region despite poor quality soils. The southern and south-eastern parts of the region are also characterized by low quality soils, they feature a higher share of forests and grasslands which increase their ecological significanceand raise their recreational appeal
The paper presents an analysis of oats phytocenosis (the crop and weeds) treated as a competitor group as concerns the species domination developing within it. The study covered oats cultivated on plots after potatoes (in crops rotation system with 25% share of oats) and twice after oats (75% share of oats in the rotation system) during the years 1990-2000. Simpson's species domination ratio and domination structure in the association identifying groups of: dominants, subdominants, influents and accessory species, were computed and studied. Relations between the studied phytocenosis features and weather conditions and oats yield were also determined. It was shown that quantitative relations in the assessed competitor associations were characterized by high variability between years and vegetation periods while no major differences were found between positions in the crop rotation systems. The density of spring phytocenosis during 11 years of studies increased resulting from increasing numbers of weeds appearing; during the late vegetation period they changed the density of associations slightly. In the spring, the groups competitive to the group of dominants consisted usually of the crop and Thlaspi arvense as well as Chenopodium album; with the passage of years their position strengthened. The enrichment of species in phytocenosis was represented mainly by an increase in numbers of accessory species. At the end of vegetation the importance of oats as a dominant increased significantly; during some seasons Chenopodium album co-dominated, however, with the passage of years the group of subdominants grew. Domination ratios for the studied competitor groups decreased with the passage of years, parallel to decrease of oats share in them. The studied features of phytocenosis showed a stronger correlation to the passage of years than the weather development. Invasiveness of weeds increased during consecutive seasons of cultivation while it showed less correlation with the density of oats. Oats yields showed a slight decreasing trend from year to year and was highly determined by the density of the entire weeds assemblage and in the spring by density and share of dominating species.
The effects of legume-cereal mixtures are usually expressed in the yield of seeds and total protein, sometimes in the yield of straw and post-harvest residues. Species composition and proportion of components in the mixture are a factor that strongly varies it. The aim of the research was determining productivity (the yield of seeds and straw as well as of the biomass of post-harvest residues) of a mixture of field pea with spring barley on the plot after potato, spring barley and after itself. The studies were carried out based on a statistical field experiment set up on rusty-brown soil, developed from silty loamy sand, deposited on slightly loamy sand and sand. The legume-cereal mixture was cultivated in six 4-plot crop rotations with its 25- and 50% proportion. In the growing season, no chemical protection was applied against diseases and weeds, however, zoocides were used against pests. It was indicated that yield of the seed mixture was similar compared to plots with crop rotation. Selection of the forecrop also did not have an effect on the straw yield, while it significantly varied the biomass of post-harvest mixture of barley with pea. The smallest quantity of residues was found after potato, while the largest in the crop rotation with field pea. In the structure of residual biomass, roots constituted lower proportion than the aboveground parts. The total production of the biomass of legume-cereal mixture, expressed in the total aboveground and underground biomass of mixture canopy was significantly higher in the crop rotation with field pea than after potato, where there occurred a significant reduction in biomass of the aboveground vegetative part of the plant.
Doświadczenie wazonowe zrealizowano w laboratorium szklarniowym Uniwersytetu Warmińsko-Mazurskiego w Olsztynie (53°46'26" N; 20°29'30" E) w latach 2003-2005 w trzech seriach, na podłożu gleby lekkiej i ciężkiej. Badano konkurencję pomiędzy jęczmieniem jarym a grochem siewnym w pięciu okresach wyznaczonych przez rytm rozwojowy jęczmienia w siewie czystym, tj. w fazach: wschodów (10-13 – według Zadoksa), krzewienia (25), strzelania w źdźbło (32), kłoszenia (55) i dojrzewania (87-91). Doświadczenie założono według schematu addytywnego w 4. powtórzeniach. W wyznaczonych okresach określono plony suchej masy różnych części roślin (łodyg, liści, kłosów, strąków, korzeni). Dane posłużyły również do wyliczenia szybkości wzrostu łanu. Współrzędna uprawa obu gatunków, na tle siewów czystych, już od początku wegetacji powodowała redukcję masy nadziemnej i korzeni. Proces ten w miarę upływu czasu ulegał pogłębieniu. Konkurencja najmniej ograniczała przyrost suchej masy w łodygach, a najbardziej w kłosach i strąkach. Rodzaj podłoża glebowego nie miał wpływu na akumulację suchej masy w roślinach jęczmienia jarego i w częściach nadziemnych grochu siewnego, w przeciwieństwie do jego korzeni, gdzie większą redukcję biomasy odnotowano w glebie ciężkiej. W mieszance obu gatunków stwierdzono spowolnienie tempa gromadzenia biomasy w całym okresie wegetacji.
The paper presents the analysis of changes in weed infestation in spring barley cultivated in the years 1990–2004 in crop rotation with a 25% proportion of this cereal (potato – spring barley – sowing peas – winter triticale), when it was grown after potato, and in crop rotation with its 75% proportion (potato – spring barley – spring barley – spring barley), when it was grown once or twice after spring barley. In the experiment, no weed control was applied. Every year in the spring (at full emergence of the cereal) and before the harvest, the composition of weed species and weed density of particular weed species were determined, and before the harvest also their biomass. Weed density increased linearly on all plots during the 15-year period. The average values confirm the increase in weed biomass in the case when spring barley was grown once or twice after this crop; however, those differences were influenced by the previous situation only during some seasons. Weed density and biomass showed high year–to–year variability and a positive correlation with the amount of precipitation and a negative correlation with temperature during the period of the study. A negative correlation between the yield of barley and weed biomass was shown.
A pot experiment, set up in an additive design, was run in order to assess the effect of Italian ryegrass on morphological traits of spring barley at different phases of its development under optimal and 50% lower soil moisture content. The following traits were measured: plant height, number of developed leaves per plant, length of ears, number of grains in an ear and length of roots. The assessment was completed during five development phases of barley (the BBCH scale): emergence (10–13), tillering (22–25), stem elongation (33–37), heading (52–55) and ripening (87–91). In 2009–2011, 3 cycles of the experiment were completed. It has been shown that Italian ryegrass did not have any significant negative effect on the morphology of spring barley’s aerial organs, although it retarded the development of roots during emergence, as reflected by their length. Water supply differentiated demonstrably the rate of growth and development of crops. Its deficit restrained the growth of spring barley throughout the whole growing season. Besides, shortage of water was responsible for a smaller number of leaves and shoots on plants, shorter ears and less numerous grains in an ear. The presence of Italian ryegrass as an intercrop, in comparison with a spring barley pure stand, did not exacerbate the negative impact of water shortage on the morphological traits of this cereal.
A pot experiment with an additive design and three series was conducted to test competition between spring barley and Italian ryegrass under different soil moisture conditions. The experimental factors were as follows: 1. type of sowing – mixed sowing and pure sowing; 2. water supply – plants supplied with water to meet their full requirements and 50% water supply reduction. The study covered five phenological development stages (BBCH) of spring barley: emergence (10–13), tillering (22–25), stem elongation (33–37), heading (52–55), and ripening (87–91). The competitive effects were evaluated based on relative yield (RY), relative yield total (RYT), competitive balance (CB), and relative efficiency index (REI). Spring barley and Italian ryegrass competed for resources throughout the growing season. Competition intensity was found to increase until the heading stage, and it decreased towards the end of the growth cycle. More intense competition was observed under reduced water supply. Spring barley dominated over Italian ryegrass from the tillering stage to the ripening stage. In mixed populations, Italian ryegrass captured the available resources more effectively than spring barley from the stem elongation stage until the end of the growing season, particularly in the treatment with optimal water supply.
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