Mineral fertilization is one of the most important components of proper cultivation technology of spring wheat. It actually determines the quantity and quality of grain yield. In 2011-2013 a strict field experiment was carried out which aimed to determine the response of chosen spring wheat cultivars to two NPK fertilization levels. In the research hypothesis it was assumed that varied rates of NPK fertilization will modify the canopy structure, the state of plant nutrition and the quantity and quality of spring wheat grain yield. Two fertilization levels were used: 80 N; 43.6 P and 83 K kg·ha^-1 (level I) and 120 N; 65.4 P and 124.5 K kg·ha^-1 (level II). The tested cultivars were: Hewilla, Monsun, Nawra, Ostka Smolicka, Waluta, Zadra, Żura. The higher rate of mineral fertilization in comparison with the lower one resulted in a significant increase in SPAD and LAI indices values, whereas it did not modify MTA index. The number of ears per 1 m² was higher on treatment with the higher fertilization level as compared with the lower. The obtained difference was significant and on average it amounted to 26 no.· m². The number of grains per ear and TGW were not modified by the fertilization factor. Spring wheat gave the highest yields in 2012 and the lowest in 2013. After the use of the higher fertilization level, the mean grain yield amounted to 5.83 Mg·ha^-1 and was significantly higher than on the treatment with the lower fertilization level (4.89 Mg·ha^-1). Plants of the cultivar Ostka Smolicka were characterized by a significantly higher LAI index in relations to the cultivar Monsun, whereas MTA index was significantly higher in plants of the cultivar Waluta in comparison with the cultivar Żura. The highest value of SPAD index was recorded in plants of the cultivars Hewilla and Ostka Smolicka, and significantly lower in the cultivar Żura. Moreover, a significant difference was indicated in SPAD between the cultivars Nawra and Ostka Smolicka. Plants of the cultivar Waluta lodged significantly heavier than those of the cultivar Nawra. More plump grains were formed by Nawra as compared with Zadra. Ostka Smolnicka was characterized by the highest yield, and Monsun, Nawra and Waluta by significantly lower yields. Also it was proved that Hewilla has a significantly higher grain yield than Nawra. Experimental factors did not have a significant effect on total protein content in grain.

The complex of Czersk Meadows, irrigated since the middle of the 19th century with the strip-flood system, is unique on the European scale. The aim of this study was to estimate the content of organic carbon, total nitrogen and dissolved fraction of organic matter in conditions of long-lasting irrigation of grasslands. The studied areas included Czersk Meadows, irrigated for more than 150 years, and the areas that were not irrigated for more than 25 years (Green Meadows). The study area is characterized by rusty soils with features of podsolization (RWbi – Albic Brunic Arenosols (Distric)). Soil samples were collected from surface and subsurface horizons: A, AE, Bsv. There were determined as follows: the total content of organic carbon (TOC), total nitrogen (Nt) as well as dissolved organic carbon (DOC) and dissolved nitrogen (DNt). Higher accumulation of organic carbon and total nitrogen was found in the humus horizon of soils of systematically irrigated meadows as compared with the soils of meadows that were stopped to be irrigated. The contents of TOC and Nt in soil samples collected on Czersk Meadows increased along with the distance from irrigation ditches. Soils of irrigated meadows were characterized by a wider TOC/Nt ratio than the soils of not irrigated meadows. Constant irrigation of meadows also resulted in a high proportion of DOC and DNt in the humus horizon (A) of soils.

The present paper reports on our observations on embryological processes occurring in the ovules of triploids: Taraxacum belorussicum (sect. Palustria) and T. atricapillum (sect. Borea). The reproduction of these dandelions comprises meiotic diplospory, parthenogenesis and autonomous endosperm development. Mature seeds contain viable embryos that provide regular seedlings. At present the importance of cytological and embryological studies of apomicts is specially emphasized because Taraxacum is one of the model genus for investigations of apomixis. It forms a polyploid complex within which there is a close relationship between the mode of reproduction and the ploidy level: diploids reproduce sexually, whereas polyploids are apomicts. Apomixis is of a great interest in plant breeding because it allows clonal seed production but asexual seeds formation by apomixis is not found in any crop plants. Unfortunately, to date any attempts at introducing of apomixis into crop species have failed. It is worth mentioning that dandelions are valuable honey plants and numerous species of Taraxacum are also used in modern herbal medicine.

The process of secondary succession is observed in the meadows of river valleys in most areas of Central Poland. Abandoned meadows are the result of demographic and economic changes in the country. As a result of secondary succession, forest communities return to abandoned pastures in Pilsia Valley. There are several scenarios of this process. In the classical model the following sequential order appears: tall herbs, tall herbs with seedlings of trees and shrubs, willow thickets and woods. Drained meadows become secondary swamps. The transition stage of turning into a forest are rushes and nitrophilous climbers (Calystegietalia sepium). In the parts of the valley which are outside the direct reach of surface water, the return of the forest is preceded by the appearance of community with the dominance of one species, which is usually Deschampsia caespitosa.

Winter wheat cv. Zyta was grown in organic and integrated farming systems as part of a field experiment conducted in north-eastern Poland in 2008-2010. The aim of the study was the assessment of the effect of different farming systems and various protective treatments on plant health status. The severity of infections caused by Septoria spp., Blumeria graminis and Puccinia recondite, affecting the leaves of winter wheat plants, was determined mainly by weather conditions and the applied cultivation system. 2009 was a rainy year which supported the development of Septoria diseases, whereas the dry year 2010 was favourable for the growth of powdery mildew of grasses and cereals. The leaves of winter wheat plants grown in the organic farming system were more often infected with brown rust, whereas plants grown in two variants of the integrated farming system were more likely to be affected by Septoria diseases and powdery mildew. The severity of stem-base diseases varied depending on the year of the study and the applied forecrop. The highest infection rates were reported when winter wheat was grown as a forecrop. The rainy year 2009 stimulated the development of stem-base diseases. The positive effect of EM biopreparation on the health status of winter wheat was observed only in the organic farming system.

Potato has a relatively shallow root system and requires significant nutrient inputs to maintain tuber productivity and quality. Efficient application of the proper type and amount of fertilizer plays an important role in achieving profitable tuber yield with minimum nutrient loss to the environment. The aim of this study was to compare utilization of nutrients from NPKMgS-type fertilizer complex from the nitrophoska (HydroComplex, Nitrophoska Blue Special, Viking 13) and amophoska group (Polimag S), and single-nutrient fertilizers (ammonium nitrate, superphosphate, potassium sulphate) by very early-maturing potato cultivars (Aster, Fresco, Gloria) on loamy sand soil. Nutrient utilization from fertilizers was calculated as a percentage ratio of the difference between the amount of nutrient uptaken by potato tubers in treatment with particular fertilizers, and nutrient uptake by potato tubers in the control treatment without fertilizers, to the quantity of the nutrient applied in particular fertilizers. With the use of complex fertilizers with microelements from the nitrophoska group, i.e. Nitrophoska Blue Special and HydroComplex, nitrogen, phosphorus and potassium utilization by potato tubers was higher than that obtained using the single-nutrient fertilizers. The use of these fertilizers produced better results for plant growth under well-watered conditions. With the use of complex fertilizers from the nitrophoska group without microelements (Viking 13) and from the ammophoska group (Polimag S), the nutrient utilization was similar or lower than with the application of single-nutrient fertilizers. The highest nutrient uptake along with potato tuber yield was reported with the application of Nitrophoska Blue Special; the nitrogen uptake was higher by 10.05 kg·ha^-1, phosphorus by 1.84 kg·ha^-1, and potassium by 11.41 kg·ha^-1 in comparison with single-nutrient fertilizers. When this fertilizer was applied, utilization of nitrogen (21%), phosphorus (9%) and potassium (23%) by very early-maturing potato cultivars was almost twice as high as with single-nutrient fertilizers. The uptake and utilization of nitrogen, phosphorus and potassium by potato tubers depended on the cultivar, and was determined by weather conditions during the potato growing season.

The aim of the study was the evaluation of the effect of diversified nitrogen fertilization: in-soil, foliar, and foliar in combination with multi-component fertilizer Ekolist, on the content and composition of protein of spring triticale grain cultivar Milewo. Field experiment was carried out at the Didactic-Experimental Centre in Tomaszkowo, which is part of the University of Warmia and Mazury in Olsztyn. Total protein content, as well as the contents of the particular protein fractions in spring triticale grain cultivar Milewo were affected by both the application of foliar additional feeding with Ekolist and mineral nitrogen dose. Nitrogen application at the dose of 80 kg·ha^-1 with Ekolist, in comparison with the same dose but without the multi-component fertilizer, attributed to the increase in protein amount by 0.72 g per 100 g of grain. The highest proportion was made of storage proteins with the advantage of gliadins over glutenins. Fertilization variants applied in the experiment resulted in a high ratio of gliadins to glutenins. Moreover, significant effect of the total nitrogen dose 120 kg·ha^-1 was confirmed in comparison with 80 kg·ha^-1 on the increase in the concentration of ωand α/β gliadins . Cultivation year affected the proportion of γgliadins and HMW and LMW glutenins in the grain. Increase in nitrogen fertilization by 40 kg·ha^-1 before sowing as ammonium nitrate contributed to the increase in ω gliadins and HMW glutenins. Additional application of Ekolist fertilization (variant with the dose of 80 kg·ha-1) caused an increase in γ gliadins and LMW glutenins.