The formation of botanical composition, phytomass and herbage quality of grass swards depending on the cutting regime and irrigation. II. Tall fescue- the qualitative data
1994
Lillak, R.
The major focus in this study was to estimate how "Zapadnaja" tall fescue in terms of its chemical composition and content of energy is suitable for the use for feeding cattle in Estonian climatic and soil conditions. Besides this the rates of changes of chemical composition and nutritive value of tall fescue as influenced by different times of the first cut, cutting frequency and irrigation were examined from 1985...1989. The experiments were carried out in Tartu, South-Estonia on a brown pseudopodzolic soil, where the content of organic matter was 1.88...2.24 per cent. Every year 44 kg/ha of phosphorus, 208 kg/ha of potassium and 300 kg/ha of nitrogen were applied to the grass-sward. The main results can be summarized as follows: 1. When the first cut was made at the beginning of the vegetative period at the tillering stage of development of tall fescue the herbage with highest content of crude protein, -fat, energy and major macroelements and lowest content of crude fibre was obtained. As the overall grass quality declined quickly with advanced development, it is necessary to make the first defoliation at the tillering or leaf tube formation stage and to use a three - or four-harvest system. 2. The accumulation of major macroelements from soil to herbage was more intensive by the application of a three- or four-harvest system. 3. Soil water regime had no significant effect upon the concentration of N, P, K, Ca and Mg in tall fescue. The accumulation of these macroelements by herbage was increased 5...25 per cent as a result of irrigation. 4. For the negative side "Zapadnaja" tall fescue appeared to have high levels of potassium as a result of which there was an imbalance between potassium on the one hand and magnesium and calcium on the other hand, ratio was 2.4...5.1:1. Therefore there is a potential of the forage to induce grass tetany in grazing cattle
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