The Eleventh Regional Wheat Workshop For Eastern ... - Cimmyt

Effect ofcrop rotation and fertilizer application on wheat yield - Amanuel et al.
treatments, respectively, at Kulumsa. At Asasa, the AE for N was relatively low across all
treatments; however, BaWW exhibited the highest AE of20.3 kg grain per kg Nat Asasa.
The AE of an incremental 20 kg P ha- I was significant at Kulumsa for only four rotation
treatments: 32.5 for RpW, 27.5 for RpWW, 19.0 for FbW and 13.5 for BaW (Table 6). In
contrast, AE was significant for seven treatments at Asasa: toe RpWW, FbW, BaW, FbWW,
FbWW, BaWW and RpW treatments exhibited AEs of 30.5,29.0,23.0,21.0, 18.0, 16.5 and
16.0 kg grain per kg applied P.
. CONCLUSIONS
The long-tenn data set generated by this experiment revealed that the first wheat following a
faba bean precursor crop either in a 2- or 3-course rotation consistently resulted in superior
grain yields in both environments. A rapeseed precursor also resulted in significant grain
yield increments in a succeeding wheat crop. The low yields obtained from the continuous
cereal rotations at both locations indicate the need to encourage the adoption of appropriate
crop rotations by peasant fanners in Ethiopia. In particular, the proportion of legumes should
be increased in the currently cereaL-dominated cropping systems. Crop rotation treatments
exerted significant effects on wheat response to applied Nand P nutrients: rotation with faba
bean minimized wheat response to fertilizer N; crop rotation, in general, enhanced wheat
response to applied P. The use of the N2 fixing leguminous crop faba bean in rotation with
wheat in the present experiment clearly demonstrated the importance of legume-cereal
rotation systems in sustaining wheat production and reducing the consumption of costly
imported inorganic N fertilizer.
ACKNOWLEDG.MENTS
The authors wish to thank Messrs. Mekonnen Kassaye and Workiye Tilahun for their
technical assistance during trial execution. This research was supported financially by the
Ethiopian Agricultural Research Organization (EARO) with the collaboration of the wheat
agronomy component of the CIMMYT/CIDA Eastern Africa Cereals Program.
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