Grassland productivity. 1. Nitrogen and soil effects on yield of herbage
1974; Volume: 13; Issue: 3 Linguagem: Inglês
ISSN
0578-7483
Autores Tópico(s)Agricultural Science and Fertilization
ResumoThe effect of incremental applications of nitrogen on herbage DM yield on a range of soils was studied on 26 sites in 1967-70 inclusive. Levels of N (kg/ha) used were 0, 115, 231, 462 in 1967; 0, 168, 336, 673 in 1968; 0, 168, 336, 504 in 1969 and 1970. Basal lime, P and K were applied to all plots. The average yield over the 4 years was 7.0, 9.3, 11.3 and 11.8 t/ha from average applications of 0,155, 310 and 536 kg N/ha, respectively. Significant responses to applied N were obtained on all sites in the first 3 years and on 23 sites in the final year. The response to the final N increment was generally not significant. It is concluded that, on average of all soils, with continuous N application and re moval of herbage, little worthwhile response is obtained from N levels in excess of 336 kg/ha. A ranking of the soils on the basis of maximum yield is given as Cork-Waterford 100; Meath-Elton 92; Clonroche 89; Macamore 87; Borris-Screen, Athy Gravel, East Mayo-Galway 84-85; Coal Measures 80; Drumlins, Deep Peat 66.
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