The paper reviews Polish literature on the applicability of some field crops grown to the production of renewable energy as fuel biocomponent (esters of higher fatty acids of rapeseed oil, bioethanol) –Part I and biomass as solid fuel – Part II. Liquid fuel biocomponents can be obtained from seed of winter oilseed rape and from surplus of cereals grain as well as from tubers of high starch potato cultivars. To meet the demand for stock, over the next 5-6 years the area of energy crops in Poland should cover 440,000-475,000 ha of oilseed rape and 470,000 ha of rye or 140,000 ha of maize or 150,000 ha of high starch potatoes. A higher long-term demand for the stock can be also satisfied by the domestic production. From the agrotechnical point of view, to enhance the capacity of stock (oilseed rape, cereals, potato), it seems most important to enhance the effectiveness of the factors governing the crop yielding and crop protection in production technology. There have been found no reports available in literature concerning the effectiveness of processing crop material into biocomponents.

Biomass for direct combustion can be obtained from short rotation willow coppice harvested in annual or 2-3 year cutting cycles and as a supplement, from some perennial crops of C₄ photosynthesis as miscant and spartina and, on a smaller scale, also from Virginia mallow. The results of studies into other potential energy crops discussed do not seem to recommend them. The research into biomass production technologies, especially solid fuels processing, are less advanced. The reports show a potential application of selected crops to production of bioenergy usually neither with a precise technical solution nor with a financial and energy analysis of the project as a whole.

Set-aside and changes in utilization of agricultural land are, in general, connected with insufficient profitability of agricultural production, urbanization of rural areas or a loss of soil productivity. The Set-aside Land Option (SLO) introduced in the European Union countries at the end of the eighties as part of Common Agricultural Policy (CAP) resulted from surplus in agricultural production. Its main purpose were equal prices on the world food market. In Poland set-aside is mainly due to a decrease in the production productivity. At the end of the nineties the area of arable land excluded from production was over 2 m ha. The present review presents the main research problems. The results of studies conducted recently in Western Europe and the United States confirm the positive effect of taking land out of production on the soil environment, surface waters, animal and plant species diversity and on the physical and chemical processes within agroecosystems.

Farming systems strongly affect soil humus. In this study some humus characteristics were used to compare the humus quantity and quality under two different farming systems. The field experiment was established in 1990 on an Orthic Luvisols in Slovakia. A higher content of organic carbon (C_T) in topsoil (13.1 g·kg^-1) was recorded in soil under ecological farming where only organic manures were applied rather than in topsoil from integrated farming (12.5 g·kg^-1) where both organic and inorganic fertilisers were applied. The quality of humus (HA : FA ratio) was similar in soils under both farming systems. Humic acids (HA) were isolated and analyzed for elemental composition, UV–VIS spectra and thermal properties. HA extracted from soil under ecological farming, as compared with HA from soil under integrated system, were characterised by a lower value of the H : C ratio and by a higher degree of internal oxidation. It shows that HA from ecological farming have higher aromaticity, humification degree and therefore are of a higher quality than HA from integrated farming. A higher aromaticity of humic acids from soil under ecological farming was confirmed by lower values of absorbance ratios (A_2/6, A_2/4 and A_4/6) compared with the other HAs analyzed. The degree of aliphaticity determined thermogravimetrically was lower in HA from ecological farming, as compared with the integrated one, and it confirmed the results of spectral and elemental analyses referring to a higher humic acids quality in ecological farming.

The response of weeds to simplified tillage systems and the nature of changes in the weed community are presented in the paper. The paper is based on the results of strict field experiments with two experimental factors applied in three-year winter wheat monoculture over 1997/98-1999/2000. The factors included: soil tillage systems (traditional (A), and three simplified systems: B) disking, C) cultivating with cultivator, D) direct sowing) and two weed control systems (harrowing by toothed harrow and harrowing + herbicides). Fundamental parameters of wheat canopy weed infestation, collected in spring and prior to wheat harvest, were used to calculate some ecological indices: relative weed abundance (Ra), Shannon’s biodiversity index (H’), and dominance index (C). Weed communities did not get significantly modified under different tillage methods, however they differed depending on the weed control method and on the years. With time under each tillage method, the dominance index increased and the biodiversity index decreased. Weed infestation was mostly caused by 6-7 weed species only, which accounted for over 4/5 of Ra index value. Apera spica-venti (L.) P. Beauv. was the most important dominant.

The present study analyzed the relationship between stem shortening with Flordimex T 330 SL and weed infestation when exposed to different levels of nitrogen fertilisation. Irrespective of the nitrogen fertilisation level, the effect of retardant used on weed sprouting and development was low. Most species did not respond to the retardant used. Chenopodium album reaching full vegetation and Apera spica-venti ripening were more intensive only in objects where the retardant was used.

The studies were carried out on the Experimental Farm at Zawady in the years 1999-2002. A field experiment followed the field method without replications. In case of both winter and spring triticale the post-harvest tillage was applied: 1) skimming – 12 cm, 2) cultivating, 3) disking, 4) without tillage (Roundup 360 SL), 5) without tillage, 6) ploughing – 20 cm, 7) disking. The first five objects were treated with the pre-sowing ploughing (winter triticale) or autumn ploughing (spring triticale). As for both forms of triticale (winter and spring), only abandoning ploughing resulted in a significant, over 30%, grain yield decrease. Simplified tillage generally increased the weed infestation. However, a significant increase in the fresh and dry matter of weeds was observed only in objects exposed to extreme simplifications. A clearly lower yielding was recorded in case of objects most infested with weeds, especially in spring triticale.

The aim of the present study was to determine the effect of three levels of the sowing density: 500, 670 and 750 kernels per square meter and two herbicides: Arleon 75 WP and Puma Super 069 EW and harrowing on the spring triticale yield and spring triticale quality. The kernel yield did not depend on the sowing density, harrowing and the herbicides used to control weeds. Total protein yield and level in kernels increased with an increasing sowing density while the starch content decreased only with the highest density (750 kernels·m^-2). The recommended dose of Arelon 75 WP and Puma Super 069 EW increased the total protein content and decreased the starch level in kernels. It was observed that half of the recommended dose of Arelon 75 WP combined with harrowing also decreased the starch content. Increasing the sowing density, although it did not increase significantly the yield of kernels, is favourable as it increases the content of protein in kernels and so kernel yield. Recommended herbicide doses of Arelon 75 WP and Puma Super 069 EW can be used in weed control on spring triticale plantations without a decrease in the yield of kernel and protein. Reducing the recommended herbicide doses by half combined with harrowing did not change significantly the kernel yield and quality either. The herbicides researched can be used interchangeably in weed control in spring triticale.

The objective of this study was to determine the effect of varied organic fertilisation of stubble intercrop, straw and stubble (the control) and three nitrogen fertilizer doses (0, 50 and 100 kg·ha^-1) with three tillage methods: traditional, simplified and direct sowing, on spring barley yield. Spring barley yielded higher when exposed to traditional tillage than to simplified tillage and direct sowing. The highest spring barley grain yield was recorded after stubble intercrop when a legume participated, while leaving straw significantly decreased the grain yield in all the tillage systems. Spring barley grown without nitrogen fertilisation after stubble intercrop yielded higher than barley after stubble or straw following the fertilisation with the dose of 50 kg·ha^-1 of N. Introducing a stubble intercrop with a participation of a legume allows for high yields of successive crops with low N fertilizer doses and for reducing a negative response of crops to simplified tillage systems.

This paper presents the results of research into the health status of winter barley cultivated in two experiments with increasing doses of nitrogen fertilisation. Powdery mildew in cereals (Erysiphe graminis) affected the leaves and root-rot (fungi complex) –the stem base with the greatest intensity. The greatest intensity of diseases was observed in both experiments with the application of the highest dose of nitrogen and the lowest intensity of diseases – in a combination with no nitrogen fertilisation. It was shown that barley protection with Tilt 250 EC preparation reduced plant infection by leaf pathogens (Erysiphe graminis, Rhynchosporium secalis, Helminthosporium teres). The crop health status was also determined by the fertilisation method applied. Higher crop infections were observed in the combination with combined mineral and manure fertilisation than in the combination with mineral fertilisation only (especially by Erysiphe graminis, Helminthosporium teres, Pseudocercosporella herpotrichoides).

The research has been carried out in 1996-2001 under the conditions of loess soil of the central Lubelszczyzna. The experiment was set up following the randomized blocks method in three replications. The analysis of field infestation was made prior to spring barley harvest with the botanical-weighing method. It has been shown that the seven-year monoculture of spring barley increased significantly the number and air-dry weight of weeds as compared with the crop rotation. Barley cultivars did not differentiate the weed infestation. The plots were mostly grown by short-lived species of the fourth and fifth degree of phytosociological constancy. Spring barley in monoculture increased the occurrence of a majority of weed species, particularly Matricaria maritima ssp. inodora, Echinochloa crus-galli, Stellaria media, Viola arvensis, Chenopodium album, Chamomilla recutita, Galinsoga parviflora, Galeopsis tetrahit and Agropyron repens.

Over 1996-1998 in the RSD Lipnik in the vicinity of Stargard Szczeciński field and laboratory experiments were carried out on light soil, of IV soil valuation class, in order to evaluate the reaction of malt and fodder barley to sprinkling irrigation and fertilisation. The sprinkling irrigation and high doses of mineral fertiliser considerably increased the photosynthesis in barley leaves; CO₂ assimilation by an average of about 50% and transpiration by an average of about 30%. Similarly the irrigation and fertilisation much enhanced the activity of nitrate reductase. Higher activity of physiological processes resulted in a luxuriant growth of barley which produced higher and thicker stalks, larger leaves and ears. Fodder barley reacted to sprinkling irrigation to a greater extent than malt barley, due to higher NPK doses, and the interaction of the two agrotechnical factors was evident.

The comparison of spring malt and fodder barley yields has shown that fodder cultivars react better to sprinkling irrigation and fertilisation, which is seen by slightly higher yields. A simplified economic analysis showed the profitability of high mineral ferilization, whereas sprinkling irrigation was not profitable even when applied with the highest NPK dose. It must have been due to an inadequate relation between the price of grain and the cost of production means. Sprinkling irrigation and fertilisation showed a clearly favourable effect on the quality of malt and fodder barley grain. Sprinkling-irrigated and well fertilized malt barley grain met the brewery standards. Similarly fodder barley grain from sprinkling-irrigated and triple-NPK-dose-fertilized plots was of high fodder quality.

The present paper covers the results of studies carried out in 1998-2001 on a good rye soil complex at the Mochełek Experiment Station which involved spring barley – winter wheat crop rotation link. There were evaluated the effects of companion crops of catch crop on the yield of spring barley (a cover crop) and winter wheat (a successive crop) as well as on the productivity of the link: spring cereal – winter cereal. Also green matter yield of companion crops was defined and their effect on cereals depending on precipitation and its distribution. Companion crops yielding, especially Fabaceae, varied greatly over the study years. It was found that the highest yield of green matter, both upon spring barley harvest and post-harvest regrowth, was noted for chicory and Italian ryegrass. Companion crops of white clover and serradella, despite lower yields, increased the productivity of spring barley – winter wheat crop rotation link by 1.5-4.1% and chicory and Italian ryegrass decreased it by 5.3-8.7%.

The objective of the study carried out over 1999-2002 on good rye soil complex soil was to evaluate the effect of fertilisation with straw, cultivation of stubble intercrops and the method of placing plant biomass in soil by varied tillage on some properties of soil arable layer in the crop-rotation link: winter wheat – spring barley. The fertilisation with straw decreased the mineral nitrogen concentration in soil in autumn. As a result of a less deep post-harvest tillage and abandoning the pre-winter tillage, soil moisture decreased, while the soil compaction as well as weed infestation of the successive crop increased. The cultivation of intercrops usually limited the weed infestation and the amount of mineral nitrogen in soil, especially with a rainfall deficit, the soil compactness could increase and its moisture – decrease. The cultivation of winter rye in stubble intercrop, with no pre-winter tillage, is limited as it leads to unfavourable changes in the topsoil properties in spring.

In 1990-2000 an experiment on average soil investigated the response of cereal mixture of spring barley and oats (50% each) and these cereals separately in pure stand to different crop-rotation positions of a 4-field crop rotation system (with 25, 50 and 75% share of these crops). The cereals returned to the same rotation position after 3 years (after potato), after one year (after potato and field pea) and once or twice after themselves. The evaluation criteria were: grain productivity per unit and its variation throughout the years and some yield structure components. Over 11 years, the cereal mixture yielded significantly higher and the yield was more stable than spring barley and oats cultivated separately. The mixed cultivation showed to be a factor easing the effects of an excessive share of cereals in crop rotation. It was found that a cultivation of the same cereal mixture after a year break did not result in a significant decrease in its productivity, while its cultivation without rotation decreased it less considerably than in spring barley and oats. The mixed fields were usually more compact than the cereals in pure stand and barley was a dominant cereal in the mixture. For both components, their mixed cultivation enhanced the length of the culm and grain plumpness and in barley – also the length of the ear.

Harvest residue of spring barley and oats cultivated in two-component mixture and in monoculture in an experiment carried out on medium soil during the years 1998-2000 was examined. The mass of residue, their structure and chemical composition were identified after different forecrops in crop rotations with an increasing share of cereals. The study took into account the roots accumulated in 30 cm deep layer of soil and stubble. It was shown that as far as the volume of organic residue and their contents of macroelements were concerned, the residue of the mixture represented the value in between the oats, which was most productive, and the least productive barley. Both in mixture and in monoculture of those cereals, the positions in the crop rotations did not result in significant differences in the contents of nutrients accumulated in the residues. The highest fertilizer value was represented by the mixture residue sown after potato, while the lowest – after pea and when the mixture followed the mixture. The share of spring barley and oats in the crop rotation increasing to 50 and 75% resulted in poorer residue; both the residue volume and the quality.

The aim of the investigation was to compare yielding and economic efficiency of crops in pure stand and mixed crops. One-factor field experiment was carried out at the Mountainous Experimental Station at Czyrna, in the vicinity of Krynica (the Beskid Niski Range) between 1996 -2002. Pure stands (4 species) and five mixtures were compared. The following crops were grown in pure and mixed stands: ‘Dukat’ covered oats, ‘Migo’ spring triticale, ‘Rodos’ spring barley and ‘Kwarta’ spring vetch. As a result of the investigation it was observed that out of both pure and mixed stands, the mixture containing spring barley and spring triticale showed the highest average grain yield. In mixtures spring barley enhanced spring triticale yielding more than oats. For spring barley in mixtures oats was more favorable than spring triticale, while spring vetch was a better partner for oats than spring barley and spring triticale. The highest economic efficiency index value was recorded for pure stand of spring barley. The values calculated for the other pure stands and mixed crops were lower and were as follows (in the decreasing order): mixture containing spring barley and spring triticale, spring triticale in pure stand, mixture containing oats and spring barley.

The research results come from a field experiment which was carried out over 1995-1997. The effect of weed infestation on potato yielding was determined by means of the coefficients of correlation and the analysis of regression. There was noted a high negative correlation between the weed number and air-dry matter and the total yield of trade fraction tubers, one tuber weight, and weight of tubers under one plant and potato plant height. The relationship was linear. For agricultural application mechanical-and-chemical weed control is recommended with a double herbicide treatment (before and after emergence) and mechanical-and-chemical weed control with a mixture of herbicides, before potato emergence.

There were carried out two glasshouse experiments which investigated a reaction of two white clover cultivars (‘Dara’, ‘Rawo’) to water stress. In the first experiment the pots were filled with mineral soil, while in the second one – with organic soil. The mineral soil moisture was maintained at the level of 35 and 70% of the field water capacity, while that of organic soil – at the level of 40 and 80% of the field water capacity. Over vegetation the intensity of photosynthesis was measured with the apparatus measuring gas exchange Li-Cor 6400 and leaf greenness index with chlorophyll meter SPAD-502. The plants were cut three times. The biomass obtained was investigated with chemical analyses. The results showed that water stress significantly limited the intensity of photosynthesis and plant yielding as well as increased the content of chlorophyll in white clover leaves. Out of the two cultivars tested, a greater photosynthesis capacity was recorded in ‘Dara’, while ‘Rawo’ leaves were richer in chlorophyll. A significant positive correlation was noted between the intensity of photosynthesis and dry matter yield and a negative correlation between the SPAD leaf greenness index and the intensity of photosynthesis. The type of soil on which white clover was grown affected the intensity of photosynthesis, yielding and chemical composition of plants, however it did not affect the content of chlorophyll expressed as the SPAD leaf greenness index.

The aim of this paper was to evaluate winterhardiness of different cultivars of Lolium perenne L. in pasture and meadow swards on peat-muck soil. The studies were carried out over 1996-2000 in two parallel experiments. Five Polish cultivars, one Polish line and three Dutch cultivars of Lolium perenne L. were involved in eleven mixtures. The cultivars of Lolium perenne L. constituted 35% of the mixtures tested and the other 65% was made up by Dactylis glomerata L., Phleum pratense L. and Trifolium repens L.; also additionally in meadow mixtures – by Trifolium pratense L. The sward species composition was determined by the botanical-and-gravimetric analysis. Winterhardiness of Lolium perenne was limited by unfavorable thermal conditions during winters, especially when used for hay production, however over the vegetation period it was followed by a fast regeneration. Mean share of Lolium perenne L. in pasture sward ranged from 45.6 to 57.8% and in meadow sward – from 24.2 to 45%. The results obtained confirm a high meadow applicability of most of the perennial ryegrass cultivars investigated on peat-muck soils of Eastern Poland and of some cultivars also to be used for hay production.

The paper presents the results of three-year investigations (1999-2001) upon the effect of different method of plant protection on the yielding of spring rape, ‘Star’ (conventional) and ‘Margo’ (F₁ hybrid). Throughout the research period the highest yield was recorded following the application of full chemical control (Butisan 400 SC + Decis 2.5 EC + Ronilan 500 SC). Classifying the biotic agents from the most to the least grain-yield decreasing, the following order was noted: insects – weeds – diseases, which was due to a high reduction of generative organs, mainly by pollen beetle (Meligethes aeneus F.), seen as a lower number of siliques on the main stem and the number of seeds per silique. Multiple regression analysis showed that the yield of seeds was determined mainly by the number of siliques on the main stem and on lateral branches.

The idea of weeds as an element supporting the biodiversity in agrocenosis led to this research whose aim was to evaluate the effect of selected agrotechnical factors, such as crop rotation, tillage method and the herbicides applied on species diversity of weed communities. The research was carried out on winter wheat and spring barley cultivated in 5 cereal crop rotations which differed in their regenerating plants selection and in tillage. The number of species at tillering and at full vegetation, Shannon diversity indicator (H) and Simpson’s domination index (C) were taken as agrophytocenosis species diversity parameters. The effect of crop rotation on the species diversity shows non-significant, especially over full vegetation, while subsoiling lowered the species diversity of weed community in both crops. The application of herbicides reduced the weed abundance but not the weed diversity.

Rumex confertus Willd., a dangerous weed, characterized by its high reproduction potential, occurs in new stands in Poland every year. Its chemical control is difficult due to the rich root system. This study offers an analysis of insects which occur on Rumex confertus Willd., as well as the contents of secondary metabolites. It was noticed that mossy sorrel is occupied by numerous herbivorous insects; generative organs were mostly damaged. The higher the damage index, the greater the content of polyphenolic acids in the plant.

The present experiment investigated the effect of incubation temperature on growth of mycelium, spore germination and on the individual biotic effect (IBE) of Trichoderma harzianum, T. pseudokoningii and T. viride fungi. The incubation temperature from 5 to 15^oC inhibited mycelium growth and sporogenous hypha formation of the isolates researched. Also the IBE value depended on temperature. All Trichoderma spp. isolates strongly inhibited the growth of pathogens only at the temperature of 20^oC.

The research carried out at the Agricultural Experimental Station of the Agricultural University in Wrocław in 2001-2003 investigated the effect of intercropping spring triticale with yellow lupine on the species composition and abundance of thrips feeding on triticale. During three years of study the greatest number of thrips in cereal ears collected at milk stage was found in the plants grown with the lowest share of triticale and the highest – of lupin. Eleven species of Thysanoptera were identified. The most numerous were Haplothrips aculeatus and Limothrips cerealium. In the seasonal population dynamics one (2002) or two (2001, 2003) periods of a higher occurrence of thrips were recorded; the first one over the ear formation of triticale (lower) and the second one – over plant ripening (higher). There was no clear effect of spring triticale intercropped with yellow lupine on the abundance of thrips feeding on triticale, however there is a tendency of a growing abundance of thrips in triticale intercropped, as compared with its pure stand.