TY  - PRO
AU  - Minale Liben
AU  - Alemayehu Assefa
AU  - Tilahun Tadesse
AU  - Tanner,D.G.
ED  - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Addis Ababa (Ethiopia)
TI  - The response of bread wheat to N and P application under improved drainage on bichena vertisols in North-Western Ethiopia
SN  - 92-9146-058-3
PY  - 1999///
CY  - Addis Ababa (Ethiopia)
PB  - CIMMYT
KW  - Drainage
KW  - Ethiopia
KW  - Fertilizer application
KW  - Fertilizers
KW  - AGROVOC
KW  - Plant response
KW  - Soil types
KW  - Vertisols
KW  - Triticum
KW  - CIMMYT
N2  - A multi-location wheat fertilizer response trial was conducted on farmers' fields on the poorly drained Vertisols of Bichena in north-western Ethiopia during 1996 and 1997. The principal objective of the trial was to determine economic optimum rates of N and P fertilizer for the high-yielding semi-dwarf bread wheat cultivar HAR 1685, using an improved drainage technology known as broad bed and furrow (BBF). The results indicate an extremely high grain yield response to N and a lesser, but significant, response to P. Bread wheat exhibited a high agronomic efficiency (AE) of N response: even at 138 kg N ha-l, AE exceeded 14 kg grain per kg applied N. The highest mean grain yield, 3317 kg ha-l, was obtained with the application of 138-92 kg N-P2O5 ha-l, representing a yield increase of 2336 kg ha-1 over the control (i.e., nil fertilizer) treatment. All crop parameters responded more to N than to P fertilizer. Under two contrasting cost/price scenarios, partial budget analysis indicated that 138-46 kg N-P205 ha-1 was the most profitable of the nutrient combinations tested. Optimum nutrient rates based on continuous economic analysis of the grain yield response surface were not in agreement with the results of the discrete analysis, primarily because of the high degree of linearity on response and the significant N by P interaction
ER  -