Integrating phytosociological and agronomic analysis to support the sustainable management of Mediterranean grasslands

The paper analyses the integration of different methodologies for assessing the grazing value of grasslands, aimed at supporting decisions for their sustainable management, that is, the long term preservation of their productive potential. The attribution of an agronomic value (specific index) to each species can be used for a preliminary evaluation of their productive potential. It can be also considered a first step in the exploitation of data already available from studies made on grasslands using a range of approaches, among them phytosociological tables. A data base file containing a collection of Specific indices for 1796 taxa, based on evaluations made by different authors, who applied the Grazing Value method in a range of environments in the Mediterranean area, has been made available on the web site http://www.agr.unian.it/(download area, ricerca)

Differences in the Morphological Characteristics of the Land Races of the Soft and Emmer Wheat in Relation to the Modern Varieties

For the organic farmers there is important question which varieties of wheat are right for organic farming in Less Favoured Areas. Modern varieties of wheat are bred in the conditions of conventional (high imput) farming. That is why the organic farmers asked about the suitability of land races of soft wheat (Triticum aestivum L.) or different species like emmer wheat grown in the past (Triticum dicoccum SCHUEBL). The paper results from the study of fourty land races, two intermediate and ten modern varieties of soft wheat in comparison to ten land races of emmer wheat at two locations in the Czech Republic. We evaluated tuft shape, length of plant, length and width of flag leaf, length and density of spike and awnedness. The modern varieties of soft wheat are characterised by a high level of uniformity. Their tuft shape is erect or semi-erect and length of plant is 60-70 cm, it does not rise the weed competitiveness. On the other hand, they have a medium or long flag leaf whose width is narrow or medium. Length of spike is medium or long. On the other hand, emmer wheat land races have the same tuft shape as forgoing modern varieties. Length of plant (89-119 cm) is the positive aspect of the weed competitiveness. Their flag leaf is narrow, but it is compesated by its length. The spike is shorter than the spike of modern varieties of soft wheat, but it is effectivelly compensated by an increased density. Intermediate wheat land races are characterised by looselly spreading tuft shape which puts the weeds down, but on the other hand, it favours the mildew because of the microclimate of soil. Its flag leaf is very short and narrow. Length of spike is medium and it is lax dense. The group of land races of soft wheat is characterised by a high diversity. The tuft shape is most frequently semi-erect. The length of plant varies from 60 to 120 cm, it usually ranges from 90 to 110 cm. Flag leaf is usually long or very long, but its width is very narrow or narrow. The spike is often long, but lax dense. Some of the evaluated varieties of landraces are proved to be suitable for organic farming from the point of view of the morphological characteristics

ALTERNTIVE PROTECTION OF BIOPOTATOES IN ORGANIC FARMING

There were tested water extracts from Syringa vulgaris and Pyrethrum parthenium. They did not prove significant differences of decrease of the air attack of Colorado potato beetle (Leptinotarsa decemlineata), the activity of eggs – laying and the occurrence of larvae in comparison to the control. Interesting trends of lower-eggs lying and a lower larvae occurrence were discovered. The liquid spray against the late blight (Phytophthora infestans) did not significantly decrease neither occurrence of late blight or the yield. The production of the bio-potatoes is only 0,2 % of all potatoes production in the Czech Republic. The aim of this experiment was to try alternative methods of regulation of Colorado potato beetle and late blight (the biggest harmfull organisms of potatoes). For biological agriculture could be also suitable water extracts. These are possible to use as protection of potatoes against unfavorable factors (Colorado potate beetle and late blight) and increase yield and quality of production

BLACK POLYPROPYLENE MULCH TEXTILE IN ORGANIC AGRICULTURE

Black polyethylene mulch is used for weed control in a range of crops under the organic system. The use of black polypropylene mulch is usually restricted to perennial crops. The trial was conducted at Experimental station of Department of Crop Production of the Czech University of Life Science Prague-Uhříněves in Czech Republic. For the experiments were used black polypropylene woven mulch (comparison wit bare soil), two varieties of early potatoes Finka and Katka. Black polypropylene textile was used in potatoes by organic agriculture and it had positive effect on soil temperature (in the depth of 100 mm). Slightly higher soil temperatures under black polypropylene mulch in the vegetation period after planting had favourable influence on earlier stands emergence. The soil water potential (in the depth of 250 mm) and also the soil water content have been beneficial for black polypropylene mulch. Significantly lower values of the soil water potentials have been found in the period after planting and at the end of vegetation. Black polypropylene mulch provided favourable temperatures and soil moisture. Post harvest analyses were focused on the determination of the yield and quality tubers from each variant

Influence of grass mulch application on tubers size and yield of ware potatoes

The aim of the experiment was to investigate the effect of grass mulch and the term of its application on the yield and quality of potatoes and weed biomass under organic system. The experiment with 2 varieties of early potatoes (Finka and Katka), 2 row spacings (28 000 and 38 000 tubers per hectare) and 2 terms of grass mulch application (after planting and after second hoeing) was carried out in the Czech Republic in 2008. Results showed that the yield was influenced mostly by mulching (55.9 %), then by variety (39.2 %) and by growth structure (4.9 %). The highest yield was reached in the variant with grass mulch applicated after planting. The yield of this variant increased statistically about 9.3 t/ha in comparison with control variant (bare soil). Results of the weed control showed a positive effect of grass mulch on weed biomass, where the lowest weed biomass was found out in variant with grass mulch applicated after planting (weed biomass was lower by 67.6 % in comparison with the control variant - bare soil)

Structural changes in lipid-free humic acids during composting of sewage sludge

Structural changes in humic acids (HAs), extracted after lipid removal from sewage sludge during composting, were investigated using various chemical methods (elemental analysis, Fourier transform infrared spectroscopy and 13C-nuclear magnetic resonance (NMR) spectroscopy). Compared to non-purified HAs, lipid-free HAs (LFHAs) exhibit higher C and N contents and high absorbance around 1652, 1540 and 1230 cm1, which indicates the intensity of the etherified aromatic structures and nitrogencontaining components. Less absorbance around 2920, 1600, 1414 and 1100 cm1 could be assigned to their low level of aliphatic compounds, mainly those with a carboxyl group. According to 13C-NMR spectroscopy, almost 45% of aliphatic structures are removed by lipid extraction and these correspond mainly to long-chain fatty acids. During composting, significant decomposition of non-substituted alkyl structures and N-containing components occurred, increasing the relative intensity of etherified aromatic structures