Succession of white clover (Trifolium repens L.) after reseeding into eutrophisated stand
1997
Novak, J. (Slovak Univ. of Agriculture, Nitra (Slovak Republic))
From 1988-1995 succession of Trifolium repens was investigated on experimental stands at 600 m above sea level on an extremely eutrophisated stand with high supply of organic fertilizer (excrement) as a result of long-term stay of young cattle on the pasture. By means of non-tillage reseeding two-component mixtures of Trifolium repens (cv. Huia) and highly competitive species of grasses were reseeded into the sod cover. In the first three years after reseeding, the known tendency of radical reduction of T. repens under the higher rates of nitrogen was not found. In spite of its relatively high content in soil (uptake by dry matter yield of above-ground phytomass varies between 183.20 -324.95 kg per ha), the portion of Trifolium repens increased compared to the initial state in the first year after reseeding. In the last two years of the trial, after a previously moderate decrease, the portion of T. repens began to increase again. After partial reduction of grass species, thinning-out of the sod was observed and in consequence T. repens (among other species) filled in empty places in the cover. Its depression did not depend on N quantity in the soil, but rather on the shading of the lower layer of the cover by the above-ground phytomass. A four-mowing system of grassland utilisation reduced the action of competively strong species by their frequent defoliation. Better light in the lower layer, the living area of T. repens, caused an increase of its weak competitive ability and reproduction by meaans of above-ground vegetative stolons
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