Sources and doses of nitrogen on forage yield of winter and summer grass species in sequential cropping

Abstract

Manure, if managed and used properly, is a good source of nutrients for crop production, and
nitrogen is the most important plant nutrient to improve forage production. The objective of this study was to compare forage production of winter species (black oat + italian ryegrass) and summer species (sorghum or pearl millet) in sequencial cropping with organic and mineral nitrogen fertilizer. The treatments consisted of a combination of two nitrogen sources: ammonium nitrate and pig slurry, with four levels of N (zero, 60, 120 and
180kg/ha), applied at the plant sowing or after the first cut. Two cuttings were made to determine dry matter yield. Results indicate that both sources of N increased dry matter yield and there was no difference between the two sources. The maximum dry matter yield with winter grasses (black oat + italian ryegrass) was obtained with doses of N between 150 and 160 kg/ha. With summer annual grasses, the response to N was linear up to
the level of 180kg/ha.