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African Crop Science Journal
African Crop Science Society
ISSN: 1021-9730 EISSN: 1021-9730
Vol. 5, No. 2, 1997, pp. 147-159
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Bioline Code: cs97021
Full paper language: English
Document type: Research Article
Document available free of charge
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African Crop Science Journal, Vol. 5, No. 2, 1997, pp. 147-159
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Grain yield of wheat as affected by cropping sequence and fertilizer application in southeastern Ethiopia
Taa, Asefa; Tanner, D.G.; Girma, Kefyalew & Gorfu, Amanuel
Abstract
Cropping systems in the Ethiopian highlands consist primarily of cereals in
rotation with grain legume and oilseed crops; the proportional allocation
among crop species varies with altitude, rainfall, and soil type. Barley
(Hordeum vulgare L.) tends to dominate in the highest altitudinal zones,
while bread wheat (Triticum aestivum L.) is more common at medium altitudes
on well-drained soils. A trial was established in 1992 at the Kulumsa and
Asasa research sites in southeastern Ethiopia to evaluate interactions
among wheat-based cropping sequences and annual applications of inorganic
nitrogen (N) and phosphorus (P) fertiliser. Rotational crops included
Ethiopian rapeseed (Brassica carinata L.), faba bean (Vicia faba L.), and
barley. The results indicated significant rotational effects on wheat grain
yield (GY), including enhanced GY in dicot vs. cereal rotations, in two
year vs. three year rotations, in first year wheat after any break crop,
and in rotation with faba bean vs. rapeseed. Interactions among cropping
sequences and N and P fertiliser were also significant. Response to N was
markedly reduced in two year rotations with any break crop, in first year
wheat after any break crop, and after faba bean, in particular; this
reflected higher soil N status in these cropping sequences. Conversely, P
response was significantly enhanced in two year rotations and in the first
wheat crop after any break crop, and in dicot-based rotations, particularly
with faba bean. Presumably, this enhancement was the result of simultaneous
improvement in soil N status and a reduction in wheat root pathogen and
grass weed populations in these cropping sequences.
Keywords
Barley, crop rotation, faba bean, grain yield, nitrogen, phosphorus, rapeseed, Triticum aestivum, weed density
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fr |
Taa, Asefa; Tanner, D.G.; Girma, Kefyalew & Gorfu, Amanuel
Résumé
Les systemes de culture sur les hauts plateaux ethiopiens reposent
essentiellement sur la rotation cereales-legumineuses-oleagineux. Les
proportions relatives des differentes cultures varient avec l'altitude, les
precipitations et les conditions edaphiques. L'orge (Hordeum vulgare L.)
domine a haute altitude, tandis que le ble tendre (Triticum aestivum L.) se
rencontre plutt aux altitudes intermediaires sur des sols bien draines. Un
dispositif experimental a ete mis en place en 1992 dans les centres de
recherche de Kulumsa et d'Asasa dans le sud-est ethiopien afin d'evaluer,
l'interaction entre le schema de rotation et l'application annuelle
d'engrais inorganique azote (N) et phosphore (P) au sein des systemes a
base de ble. Le colza ethiopien (Brassica carinata L.), la feve (Vicia faba
L.) et l'orge ont ete utilises comme cultures de rotation. Les resultats
montrent un effet significatif de la rotation sur le rendement en grains du
ble (RG): une rotation ble-dicotyledones se traduit par un RG plus eleve
qu'une rotation ble-cereales; un cycle de rotation de deux ans conduit a un
RG plus eleve qu'un cycle de trois ans; le RG augmente apres n'importe
quelle culture de rotation; le RG de ble en rotation avec de la feve est
superieur a celui de ble en rotation avec du colza. On observe egalement
une interaction significative de la rotation culturale-fertilisation N et
P. La reponse a la fertilisation N connait une importante diminution dans
une rotation de deux ans quelle que soit la plante utilisee en rotation; on
observe egalement une reduction en premiere annee apres n'importe quelle
plante alternative, dans les rotations ble-dicotyledones et plus
particulierement dans le cas de la feve. Ces resultats refletent la plus
haute teneur du sol en azote dans les schemas de rotation consideres.
Inversement, la reponse au phosphore augmente dans les rotations de deux
ans, pendant la premiere annee apres n'importe quelle plante alternative,
et dans les rotations a base de dicotyledones, en particulier la feve. On
suppos que cette augmentation correspond aux effets combines de ces schemas
de rotation : amelioration du bilan azote dans le sol, reduction des
populations d'adventices et de pathogenes de la racine de ble.
Mots Clés
Azote, ble, colza, densite d'adventices, feve, orge, rendement en grains, rotation, phosphore, Triticum aestivum
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© Copyright 1997 - African Crop Science Society
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