Abstract:
To evaluate the interaction
effects of planting date and different levels
of nitrogen fertilizer on sorghum (Sorghum
bicolor var. Speed feed) forage production,
an experiment was conducted in split plots
based on a complete randomized block
design in Agricultural Research Station of
Khorramabad, Lorestan province, Iran. The
experimental treatments comprised of three
nitrogen fertilizer levels of control (N0),
100 (N1), and 150 kg per hectare (N2),
assigned to main plots and three sowing
dates of T1 (June, 10th), T2 (June 26th) and
T3 (July 11th) assigned to subplots. Results
showed that in sum of two harvests, the
yield of hay, forage, leaf and shoot hay
weigh in second planting date and N2 and
N3 level of fertility was higher than all
treatments. In the case of quality treatments
the percent of crude protein in first harvest
had the most amounts in first and second
planting date and N1, N2 and N3 fertility
levels. Crude fiber percentage in first
harvest of second planting date was highest
in N1, N2 and N3 levels of fertility.
Treatment interactions had not any
significant effect for crude fiber. The most
ash percent was observed in first harvest
and N1, N2 and N3 fertility level. In second
harvest time N2 and N3 fertility levels were
superior to the rest. Also, fat percentage in
first and second planting date and N1, N2
and N3 increased than the control fertility
treatment.
