Effects of nitrogen fertilization and cutting frequency on the mineral content of a natural meadow
1998
Kessler, J. (Eidg. Forschungsanstalt fuer Nutztiere, RAP, Posieux (Switzerland)) | Jolidon, V.
In a long-term trial with a natural meadow situated at 1000 m above sea level, four experimental plots were fertilized with varying levels of mineral nitrogen. Per growing season and ha, 0, 55, 110 and 165 kg of N were applied. Each plot was additionally split into three cutting frequencies, i.e. 2, 3 and 4 cuts a year. The following parameters were recorded; botanical composition and nutrient and mineral content. The results implicate an increasing proportion of grasses along with increasing levels of fertilizer at the expense of legumes. On the other hand, the proportion of herbaceous dicotyledons remained constant for the most part. Fertilizing intensity had no significant effect on the energy content, P, Mg and Na concentration of the feed. A higher protein content was measured in feed samples of the first cut. For the following cuts though, comparable protein contents were observed across all N levels. Ca concentration decreased with increasng N input by 13 to 27 % depending on the number of cut. A slight reduction was also observed for K. The higher cutting frequency resulted in a distinctly higher nutrient and mineral (Ca, P, Mg and K) content of the feed. The plots cut four times contained on average and depending on parameter between 15 and 63 % higher concentrations compared to plots cut two times. Across all cutting frequencies, Ca and Mg contents markedly increased between the first and second cut. The increase amounted to 53 % for Ca and 39 % for Mg. Between the second and the following cuts, this evolution was somewhat attenuated.
显示更多 [+] 显示较少 [-]