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

Effects ofsurface drainage methods on yield ofbread wheat on Vertisols - Yesuf et al.
was recorded and the grain yield was adjusted to 12.5% moisture content before statistical
analysis. Eventually, data were subjected to statistical analysis using the MSTATC statistical
package, and differences between means were separated by the LSD test at the 0.05 level if
significant treatment effects occurred.
RESULTS AND DISCUSSION
The first year (1993) results indicate, as apparently seen in Table 2, significant differences in
grain yield both at Sagure and Arsi-Robe with a grain yield advantage of 1580 kglha
(+ 122%) and 560 kglha (+56.9%), respectively, for broad bed and furrow (BBF) over the flat
seedbed. At Sagure, the straw yield was significantly higher, 1450 kglha (+29%), for the BBF
plots than the flat seedbed. Likewise, significantly taller plant height, 20.3 cm (+22.1 %) and
9 cm (+11.5%) was recorded from BBF plots than the flat seedbed at Sagure and Arsi-Robe,
respectively. This higher plant height from BBF plots contributed to the straw yield increase.
Moreover, the BBF drainage method increased plant height by 12 cm (12%) over the RF.
Even though there were increases in straw and grain yield from BBF plots over the ridge and
furrow (RF) drainage method at both locations, the difference was significant only for grain
yield at Arsi-Robe (Table 2).
During the 1994 cropping season at Arsi-Robe, as shown in Table 3, a grain yield advantage
of 460 kglha (+98%) and 220 kglha (+46.8%) were obtained due to BBF and ridge and
furrow, respectively, over the flat seedbed. During the same cropping season, the result at
Sagure indicate a significant variation in grain yield with an additional yield of 1290 kg/ha
(+137%) and 610 kg/ha (+64.9%) using BBF and RF drainage methods in comparison with
the flat seedbed, respectively. Although there was an increase in straw yield at both locations
for BBF and RF, the result was not significant. A higher plant height, 13.3 cm (+24.2%), was
recorded from BBF plots relative to the flat seedbed at Arsi-Robe. Similarly additional plant
height of 8.7 cm (+9.7%) and 4.7 cm (+5.2%) was recorded from both BBF and RF drainage
methods, re~pectively over the flat seedbed at Sagure (Table 3):
Furthermore, in 1995 an extra grain yield of 940 kg/ha (+96.8%) was obtained using BBF as
compared with the flat seedbed at Arsi Robe. At Sagure, the grain yield advantage was 620
kglha (+40.4%) and 320 kg/ha (+20.4%) using BBF and RF drainage methods, respectively,
relative to the flat seedbed. The straw yield was significant during this season, with an
increase of 4190 kglha (+162%) and 3130 kg/ha (+102%) at Arsi Robe and 4355 kglha
(+186%) and 1940 kg/ha (+82.1%) at Sagure using BBF and RF drainage methods,
respectively, compared with the flat seedbed. Moreover, significantly higher plant height was
recorded from BBF plots which was 15.4 cm (+18.9%) and 17 cm (+18.4%) over the flat
seedbed at Arsi Robe and Sagure, respectively.
Interestingly, the combined statistical analysis over years (Table 5) revealed that an extra
grain yield of about 1200 kg/ha and 700 kglha over the control treatment were obtained using
BBF and RF surface drainage methods at Sagure, respectively. Likewise, grain yield
increases of 660 kg/ha and 170 kglha in comparison with the control treatment were obtained
using BBF and RF surface drainage methods at Arsi-Robe, respectively.
The higher clay content, relatively level gradient and inherent poor soil fertility at Arsi-Robe
than Sagure (Table 1) basically elucidate the lower yield in the former location. Even though
grain yield was generally low at this location, the result obtained with BBF was encouraging
and significantly improved.
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