Based on the literature data, types of morphological and physiological changes occurring in plants during the process of autumn hardening were discussed, as an expression of adaptations to overwintering. They indicate that the level of plant preparation for surviving winter depends on the photosynthesis intensity, leaf area index (LAI) and the development of aboveground part and root system. It was assumed that the use of liquid humic fertilizers (LHF) for seed dressing and in the form of foliar application performed after emergences will have a favourable effect on intensification of processes which favour plant frost hardening. In two field experiments with winter wheat cv. Širvinta conducted in Lithuania in systems of conventional and organic farming in 2010 and 2011, a number of analyses were performed on young plants. In the aboveground part, dry matter of leaves, LAI, the content of chlorophyll and carotenoids were determined, and gross productivity of photosynthesis was calculated, whereas in the underground part – the root area, their diameter and total length. It was shown that the application of LHF affects an increase in values of evaluated biometric indices, and thus, indirectly, contributes to enhancing the potential resistance of plants to stress induced with low temperature. The following ranking of plant responses to the combinations of LHF use in both cropping systems was established (in descending order of favourable effects): 1) pre-sowing seed dressing – the organic farming system, 2) seed dressing and foliar spraying – organic farming system, 3) without preparation – organic farming system, 4) pre-sowing seed dressing – conventional farming system, 5) foliar spraying – organic farming system, 6) without preparation – conventional farming system. This ranking was established based on the presented multi-objective optimization analysis MULTIMOORA.

Research was carried out in years 2007-2009 on the basis of field experiment in split-plot design, in three repetitions. Monoculture lawn was set up for the experiment. In pure sowing, four species of lawn grass were studied: perennial ryegrass, red fescue, common meadow-grass, and common bent. In the experiment, the following factors were applied: bedding type: a – no hydrogel „0” –control plot; b – with the addition of hydrogel at the depths of 5 cm, 10 cm, and 15 cm; soil cover: a – cultivated soil (P); b – horticultural peat (T). At the end of each growth period, turf samples with root systems were collected from the plots at the depth of 10 cm. On their basis, the assessment of root dry matter was carried out and the number of roots was calculated on each turf block. In the particular research years, both the number of shoots and root mass formed by the studied monoculture lawns were diversified in relation to the bedding type. In the first research year, on the bedding with 5 cm depth of hydrogel placement, the studied monocultures formed the highest root mass, and in the second year the highest shoot number. Horticultural peat cover in both research years increased both the number of shoots and the root mass of the studied monoculture lawns.

In the seasons 2008/2009-2010/2011 a strict field experiment was conducted aiming at the estimation of response of winter oilseed rape hybrid cultivars to different cultivation intensity. It was found that a higher level of cultivation technology in comparison with the lower affected a significant increase in the seed yield by 0.5 Mg·ha^-1, i.e. 11.9%. This resulted from a significant increase in the number of pods per plant and thousand seed weight. Plant density before harvest per 1 m² and the number of seeds per pod showed only an upward tendency. Higher level of cultivation technology did not modify significantly the content of protein and fat in seeds. However, fat yield per 1 ha was significantly diversified. The cultivar Exotic F1 was characterized by significantly higher parameters of such features as: overwintering, the number of seeds per pod and TSW. The cultivar Visby F1 in turn was characterized by a significantly higher number of pods per plant and a higher fat yield.

The aim of this study was to estimate the effect of fertilizer UGmax on the energy, protein and mineral value of feed obtained growing cocksfoot grass, perennial ryegrass and meadow fescue. Experiment with cultivation of those plants was established in 2007. To each of rings with a diameter of 36 cm and height of 40 cm, filled with soil material, 8 seeds of one of the studied species were sown. After seed germination, when seedlings achieved the 2-3 leaf stage, negative selection was performed by removing 4 the weakest plants. Next the experimental factors were introduced in the form of the following fertilizing combinations: B1 – soil fertilizer and mineral fertilization, B2 – only mineral fertilization. The experiment was carried out in 2008-2010. Three cuts were harvested each year. In the last two years of the experiment the chemical analysis of yield dry matter was performed. Obtained results were used for calculating the following parameters of energy and protein value: UFL – feed unit for lactation, ULV – feed unit for maintenance and meet production, PDI(N) –protein digested in the intestine plus protein of microorganisms, calculated on the basis of availability in availability of nitrogen from feed in the rumen, PDI(E) –protein digested in the intestine plus protein of microorganisms, calculated on the basis of energy from feed available in the rumen. Moreover, on the basis of macroelement content the Ca : P and K : (Ca + Mg) ratio was determined. Studied species were characterized by a similar content of PDI(E). All species were characterized by the too wide K : (Ca + Mg) ratio; the ratio of calcium to phosphorus was the most favourable in the dry matter of meadow fescue. Soil supply with the fertilizer resulted in an increase in UFL value and content of PDI(N), but it did not contribute to diversifying ULV, PDI(E) and ionic ratios. Supplying soil with microorganisms did not contributed explicitly to improvement of feed value of analysed grasses in individual cuts.

The research aim was to evaluate the productivity of two winter oilseed rape cultivars, Adam and Poznaniak, in three localities in the south of Poland: Głubczyce, Pawłowice and Prusy. The scope of comparisons was broaden through a detailed biometrical analysis of plants and the spectral properties (GAI, LAI and SPAD) of canopy, which determine oilseed rape productivity. At the optimal plant density of two hybrid cultivars of winter oilseed rape: Adam and Poznaniak, three groups of plants differing morphologically and productively were identified. Strongly branching winter oilseed rape of large biomass determined the final density only in 27.2%, but it had the biggest share in seed yield per area unit, reaching 52.5%. The share of small plants of oilseed rape in the canopy reached 37.6%, but they played a minor role in the creation of seed yield. High dynamics of development ratio of winter oilseed rape plants and canopy led to the increased height of plants which, however, was accompanied by a lower number of branches and siliques and a diminished diameter of main shoot and lateral branches.

The scientific literature rarely describes the harvest index of winter oilseed rape, most probably due to difficulties in its estimation, resulting from the cracking of siliques. Our work aimed at evaluating the harvest index of winter oilseed rape, depending on the cutting height of plants of different size categories, described in the 1^st part of our work. Plants harvested from the field were dried, weighed and then 10 cm sections of the main shoot were cut off, simulating crop cutting during combine harvest. The obtained sections of plant shoots were weighed and a diameter of each was measured individually. Due to the specific distribution of dry mass in the lower section of the main shoot, an improvement of the harvest index value with raising the height of cutting the plants was obtained. Cuts at height of 60 cm increased the harvest index value by 0.08-0.09. Moreover, cutting oilseed rape at height of 60 cm is technically easier and fragments of the main and lateral shoots are left on the field as high stubble of an estimated mass of 1967.5 kg·ha^-1. Moreover, this technological solution may optimize harvesting, due to speeding it up.

Catch crop cultivation with the aim of incorporation should be a constant element of improving soil fertility. The most frequently recommended type of green manures for vegetables is stubble catch crops. It is not always possible to sow plants at the optimum date, that is in the second half of July. The aim of the study was to determine the yield of fresh and dry matter of stubble catch crops and macroelement accumulation in them depending on the sowing date. The experiment was carried out in central-east Poland. In years 2004-2006, the yield of fresh and dry matter and macroelement contents were estimated in the following catch crops: phacelia (Phacelia tanacetifolia Benth.), amaranth (Amaranthus cruentus L.), sunflower (Helianthus L.), seradella (Ornithopus sativus), and faba bean (Vicia faba L. ssp. minor). The seeds were sown on three dates: July 21^st, August 4^th, and August 18^th. In the third decade of October, plant samples were collected in order to estimate the yield of fresh and dry matter, as well as macroelements in the catch crops. The amount of biomass and macroelement content depended on the length of catch crop growth season. The highest organic matter yield and macroelement contents were characteristic for the catch crops sown on July 21^st, and the lowest ones for the catch crops sown on August 18^th. Due to high fresh and dry matter yields, sunflower was the best species to be sown on July 21^st, sunflower and phacelia on August 4^th, and phacelia on August 18^th. Faba bean accumulated the highest amounts of nitrogen and phosphorus in the dry matter. Sunflower accumulated the highest total mass of macroelements (N + P + K + Ca + Mg) in the dry matter yield. The smallest percentage decrease in dry the matter yield and amount of macroelements as a result of delaying the catch crop planting date was found for seradella.