EFFETS DE LA DENSITE DU PEUPLEMENT ET DE L’APPORT DES ELEMENTS N, P ET K SUR LA PRODUCTION D’ENSILAGE DE MAIS DE MATURITE DIFFERENTE

The experiment was designed to measure the effect of corn maturity, plant density, nitrogen, phosphorus and potassium fertilization on corn silage production. Funk’s G 4252 corn hybrid planted 10 cm apart in rows 75 cm apart produced an average of 18,325 kg/ha of dry matter over 4 yr, when fertilized with 200 kg/ha of N. Nitrogen fertilization, plant density, and choice of hybrid were the most important factors in dry matter production. Yield increases of 30% were associated with a 3% decrease in quality. Optimum yields were predicted for plant densities of 133,000 pl/ha with 180 kg/ha of N. There was no significant response to P and K fertilization. Yearly applications of P at 50 kg/ha allowed an increase in available P in the soil. Even with yearly applications of K at 200 kg/ha, a constant decrease in soil exchangeable K content was observed.