Effect of fertilization and its absence on botanical, productive, and qualitative characteristics of permanent grassland
2001
Jancovic, J. | Slamka, P. | Vozar, L. (Slovenska Polnohospodarska Univ., Nitra (Slovak Republic))
Field experiments in four replications were established on permanent grassland of Lolio-Cynosuretum typicum association in Strazov Hills (600 m above sea level). An influence of graduated N-fertilization (1986-1993) and its following absence (1994-1996) on content of mineral elements, botanicaland production characteristics were investigated within the following 5 variants: 1) without fertilization, 2) PK-fertilization, 3) PK+60N, 4) PK+120N, 5) PK+240N. Fertilization with P (35 kg/ha) and K (70 kg/ha) was constant in all fertilized variants. In the second period of fertilization the yields of dry matter were reduced by 28-49% as a consequence of changes in botanical composition and mainly by the influence of unfavorable weather conditions. There was not achieved suitable content of P in DM required for animal nutrition. K was accumulated in DM in amounts which exceeded required concentrations. However, with thw rate of 240 kg/ha N its content in DM decreased to the level of unfertilized control variant. After omitting the fertilization (1994-1996), significant changes in botanical composition as well as in DM production and its quality were observed and determined
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