Non-tillage rejuvenation of ruderal grassland though reseeding. 4. Changes in mineral content in above-ground biomass
1995
Novak, J. (Vysoka Skola Polnohopodarska, Nitra (Slovakia). Katedra Krmovinarstva)
Over 1988-1991 changes of mineral matter concentration and the proportion of dry matter of above-ground biomass after reseeding into the extremely eutrophisated stand (variants A1-A3) were observed and compared with semi-natural and ruderal grassland cover without reseeding (variants K and K0) at an altitude of 600 m above sea level. After reseeding, the phosphorus concentration was kept at a relatively high level and its deficiency was recorded only in the semi-natural grassland in the last year of the experiment. After the radical reduction of the potassium content in the soil, its concentration decreased also in the above-ground biomass, but its concentration was still 6-times higher than the optimum ruminant requirements. The levels of calcium and magnesium increasd to optimal values due to the clover proportion in the cover. Lack of natrium in the above-ground biomass was evident. The content of the elements in the semi-natural grassland cover was similar, though a bit lower. Antagonism between natrium and potassium was observed. If the concentration of natrium in dry matter increased, the content of potassium rapidly decreased and vice versa. This antagonism was not confirmed with the A3 variant, nor with the semi-natural grassland cover. The P:Ca ratio widened to an optimum value after reseeding. Phosphorus deficiency was found in semi-natural grassland cover only in 1991. The ratio Na:K was unfavourable during the whole period observed. The (Ca+Mg):K and (Ca+Mg):(Na+K) ratio were wider in comparison with the norm. Similar relations were also found in the eutrophisated stand without reseeding
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