000			03133nam a22004097a 4500
001			G70405
003			MX-TxCIM
005			20240827180235.0
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020			_a92-9146-058-3
040			_aMX-TxCIM
072		0	_aE10
072		0	_aF04
090			_aLook under series title
100	1		_9724 _aTanner, D.G. _uRegional Wheat Workshop for Eastern, Central and Southern Africa, 10; University of Stellenbosch, South Africa; 14-18 Sep 1998
110	2		_aCentro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Addis Ababa (Ethiopia)
245	0	0	_aDetermination of economic optimum fertilizer levels using discrete and continuous analytical methods
260			_aAddis Ababa (Ethiopia) _bCIMMYT : _c1999
340			_aPrinted
520			_aThe determination of economic optimum fertilizer rates is fundamental to profitable bread wheat (Triticum aestivum) production. However, the derivation of economic optimum nutrient rates is complex and is dependent upon fluctuating nutrient and grain prices and changing crop management practices. Economic optimum N and P205 nutrient rates were determined following discrete and continuous analytical methods using data generated in a series of on-farm fertilizer trials conducted in Ethiopia during 1988-90 and 1995-97 across a range of agro-ecologies. The data were first subjected to ANOVA and then regression coefficients derived from response surface equations were used to determine the continuous economic optimum fertilizer rates. Discrete analysis of the actual N-P205 treatments following partial budget methodology was used to determine the discontinuous economic optimum rates. Optimum N and P205 levels for each agro-ecological zone were established based on specified ranges for nutrient and grain prices using both methods. The optimum rates generated by the two analytical methods lacked close agreement for the obvious reason that the continuous method is based on a smoothed regression curve while the discrete method is based on actual data points. However, the relative ratios of N and P205 rates were generally consistent between the two methods. The use of regression-derived response coefficients in continuous economic analysis facilitates the construction of dynamic and robust recommendation tables for dissemination to extension staff. Furthermore, the continuous method facilitates interpolation thereby accommodating intermediate price levels.
546			_aEnglish
591			_a0007|AGRIS 0101|R99-00CIMPU|AL-Wheat Program|AL-Economics Program
595			_aCPC
650	1	7	_aCrop management _gAGROVOC _91061
650	1	7	_aEconomic analysis _gAGROVOC _91088
650	1	0	_aEthiopia
650	1	0	_aFertilizer application _91110
650	1	7	_aFertilizers _gAGROVOC _91111
650	1	0	_aPrices
650	1	0	_aProduction factors
650	1	0	_91296 _aTriticum aestivum _gAGROVOC
653	0		_aCIMMYT
700	1		_aAsefa Taa, _ecoaut. _9416
700	1		_aKefyalew Girma, _ecoaut. _9155
856	4		_yOpen Access through DSpace _uhttp://hdl.handle.net/10883/1244 _3Complete source through Dspace
942			_cPRO _2ddc
999			_c4497 _d4497