Effect of nitrogen on the production of grasses in permanent pasture swards
Paru en 1977 dans Fourrages n°71 (page 71 à 82)
Auteurs : Daget-Bertoletti L.
Co-auteurs : Daget P.
Two series of covering measurements by the all the species of five permanent postures were carried out during five years. Nitrogen fertilizer dressings of 160 and 240 units were compared with a dressing of nil.
A variance analysis according to a factorial model showed that the application of nitrogen brings about a linear increase of the average contribution of the grosses, increases the effects of climatic hazard, and that this influence is variable from one trial to the other.
It is shown that, in detail, the larger contribution of grosses with higher rates of nitrogen is according to an increasing logistic law : from one posture to the other, the law is the same, end the observed differences correspond to different segments of the curve. Moreover the analysis shows that the minimal percentage for the contribution of grasses is 25 %.