New uses of clover-grass mixtures in the structure of fodder crops on arable land

The use of clover-grasses in the structure of fodder crops grown on arable soil, especially those with intergeneric hybrids as the main component part, could avert the negative current trend, i.e. further decreasing the area of perennial fodder plants or fodder crops as a whole on arable soil. They have an irreplaceable role in crop sequences and in preserving the cultural character of the countryside, above all due to the fact that they improve soil fertility and microbial life in the soil and that they have an excellent pre-produce value, and, at the same time, they are applied in various farming systems (both conventional and ecological) and in various climatic conditions, and agricultural businesses are well equipped for growing, harvesting and storing them. In the Czech Republic, the area of fodder crops grown on arable soil was decreased from 1,019.9 thousand hectares to mere 396.7 thousand hectares between 1980 and 2009, which is 15.6 % of the total area of arable soil whereas perennial fodder plants only take up 8.5 %. Fodder from clover crops and clover-grass growths on arable soil are one of the main resources of voluminous fodder for dairy cows. Most of this fodder is preserved through a fermentation process (silages, hay storage); a smaller part is fed as fresh fodder, or serves for production of hay. Silages made with perennial fodder plants are the most important source of both proteins and other nutrients for ruminants, especially for high-yielding milch cows. The basis of fodder production systems are the conservative elements of the landscape area (geomorphology) in combination with the progressive elements (weather conditions, plants and human labour) and relict ones, the representative of which is the soil. The fodder production systems in Europe are divided into five main fodder production zones. From this point of view, the areas where short-term clover-grass mixtures are grown on arable soil could be classed with Zone 4, i.e. intensive fodder production and cattle breeding. This characterisation corresponds with the Vysočina Region (the Czech Republic), which is the focus of our work even though extensive breeding can be found in this area on a smaller scale as well. Therefore, our aim was to verify the production and qualitative parameters of the fodder crops and mixtures included in the test in chosen agricultural businesses in the Vysočina Region and to recommend the most suitable variant for the given area. A statistically significant correlative relationship (P < 0.05) was proved between the net energy for lactation contents and the percentage of organic matter digestibility. The evaluation of the production parameters evidently shows the favourable influence of the grass component part or of intergeneric hybrids on the stability of dry matter yield per hectare as well as on the stability of individual nutrients.