Abstract:
The experiment was undertaken to assess Rhodes grass yield and nutritional quality at different
harvesting days and levels of N fertilizer application grown under irrigation at Gewane, Afar
region. The field experiment was arranged in a 3 x 4 factorial randomized complete block design
with three replications. The treatments were three levels of harvesting days (60, 90 and 120 days) and
four level of N fertilizer application (0, 23, 46 and 69 kg ha-1 ). Plant height (PHT), number of tillers per
plant (NT), number of leaves per plant (NLP), length of leaves per plant (LLP), leaf to stem ratio (LSR),
number of internodes per plant (NIP), length of internodes per plant (LIP), number of internodes per
tiller (NIT), DMY and CPY significantly (P < 0.01) increased as the level of N fertilization and days
of harvesting increases. However, except for the length of internodes per plant (LIP), interaction
effect is not significant for all the parameters listed above. The highest mean dry matter yield
(DMY) recorded was 17.58 and 16.54 ton ha-1at 120 days of harvesting and 69 kg ha-1N fertilizer
rates, respectively. The crude protein content (CP), calcium (Ca), phosphorus (P), and total ash
content significantly (P < 0.01) increased as the level of N fertilization increases but declined as days
of harvesting increases; however, except for the crude protein(CP) interaction effect is not
significant. The dry matter content (DMP), neutral detergent fiber (NDF), acid detergent fiber
(ADF),acid detergent lignin ( ADL), in vitro dry matter digestibility (IVDMD) were significantly
different (P<0.01), for harvesting days and N fertilizer rates; however, except for NDF, interaction
effect is not significant for all mentioned. The highest mean CP content recorded was 15.65% and
15.24% at 60 days of harvesting and 69 and 46 kg ha-1N fertilizer rate. The highest mean IVDMD
recorded was 65.10% and 57.11% and 56.62% at 60 days of harvesting and 69 and 46 kg ha-1N
fertilizer rate, respectively. Chloris gayana with N fertilizer application of 69 kg ha-1 and 120 days
of harvesting was recorded high dry matter yield; while N fertilizer application of 69 kg ha-1 and 60
days of harvesting had more crude protein content and IVDMD. So, the results obtained in the present
study revealed that optimum stage of harvesting at 90 days and 69 kg ha-1levels of N fertilizer application
can play important roles in improving yield and nutritive value of Rhodes grass
