Abstract:
In Ethiopia, Oats (Avena sativa L.) is widely grown for both grain and forage production and
field pea (pisum sativum L.) is grown for grain production. This study was aimed at
evaluating the effect of three different oat: field pea row arrangements (RA) (1:1, 1:2 and
2:1) and three different level of nitrogen fertilizer application (0, 23 and 46 kg/ha) on yield
and chemical composition of oat and field pea intercropping with factorial arrangement in a
Randomized Complete Block Design with three replicates. Replicated plots of pure oat and
pure field pea at the three different levels of nitrogen applications (0, 23 and 46 kg/ha) were
included in the factorial treatment combination as negative control treatments. Plot size of
3x2m (6 Inter-row spacing of 30 cm was used throughout the study. The spacing
between the plots and replications (blocks) were 1 and 1.5m respectively. Soil samples were
collected before sowing and after harvesting for soil physico-chemical analysis. Data
collected on Agronomic and yield performance, and chemical composition of the forages
were analyzed with general linear model (GLM) procedure using SAS software (SAS, 2009
version 9.3). The results obtained indicated that maximum mean plant height, number of
tillers per plant and significantly higher number of leaves per plant were recorded from the
experimental plots with RA of either 1:1 or 1:2 receiving 46 Kg of N2 ha-1. Significantly
(P<0.05) higher mean fresh biomass yield of 42.22 t/ha was obtained at RA of 1:2 receiving
46 Kg N2 ha1 and significantly (P<0.05) lower biomass yield of 29.83 t/ha was harvested
from sole oat plots without N2. Maximum mean total DMY of 7.42t/ha1 was recorded at RA of
1:2.Whereas the total DMY of sole oat was significantly reduced to 5.22 t/ha. On the other
side, significantly higher (P<0.05) mean total DMY of 7.67 t·ha-1 was harvested from
experimental plots receiving 46 kg N2 ha-1 , whereas the minimum mean total DMY of 5.32 t
ha-1 was recorded from the treatment plots without N2. Seed yield was significantly
(P<0.05) higher for plots with RA of 1:1 (3.98 t/ha) and 1:2 (3.96 t/ha) receiving 46 kg N2
ha-1. Maximum CP content of 13.06% was recorded from plots with RA of 1:2 receiving 46
kg N2 ha-1 and the lowest CP content of 8.31% was recorded from plots planted to sole oat
without N2. The highest NDF content at 50% flowering of 56.48% was recorded from plots
without N2 and the lowest NDF value of 51.94 was recorded from plots receiving at 46 kg N2
ha1. The economic analysis indicated that the interaction of 46 kg N2 ha-1 at 1:2 RA produced
net benefit of 405,477.44 ETB ha-1 with MRR of 32,286.98%, which could be recommended
as profitable treatment to Oat-field pea producing farmers in the study area. In summary,
the results of the current study indicated that Oat: field pea intercropping at 1:2 RA and
application of 46 Kg N2 fertilizer ha-1 was found to be promising in terms of agronomic
characteristics, yield parameters and feed quality. Further research on effect of N2 rate and
RA on DMY and chemical composition of oats and seed yield of field pea for its performance
over years, across diverse agro-ecologies is also vital to more fine-tuned recomme
