Low efficiency of nitrogen use by maize on smallholder farms in sub-humid Zimbabwe
Mushayi, P.T.
Low efficiency of nitrogen use by maize on smallholder farms in sub-humid Zimbabwe - Addis Ababa (Ethiopia) CIMMYT|EARO : 1999 - p. 278-281 - Printed
Nitrogen (N) is the major nutrient limiting maize production in Zimbabwe. Surprisingly, little information is available about the maize yield response to N that smallholder farmers obtain on their fields under their own management. On-farm trials were conducted in five sub- humid smallholder areas of northern Zimbabwe during 1996/97 and 1997/98 to establish the response of maize to N. N fertilizer, at rates from zero to 125 kg N/ha (at 25 kg intervals), was applied to farmers' maize crops and to researcher-managed crops planted on farmers' fields. In twelve researcher-managed trials, three maize genotypes: SC401 (short season hybrid), SC601 (medium maturity hybrid) and ZM607 (an open- pollinated experimental population) were used. In 22 farmers' maize crops, N was applied by the farmer to the crop selected by the farmer using the farmers' normal methods and timing. During the very wet 1996/97 season, maize yields in the researcher-managed trials averaged 708 kg/ha without fertilizer and up to 2261 kg/ha with 125 kg N/ha, and from 506 kg/ha without fertilizer up to 1076 kg/ha with 125 kg N/ha in the farmers' crops. In 1997/98, low to medium rainfall led to higher yields. Maize yields in 1997/98 averaged 1205 kg/ha without fertilizer up to 3199 kg/ha with 125 kg N/ha in researcher managed crops, while those in farmers' fields averaged 1096 kg/ha without fertilizer and up to 2210 kg/ha with 125 kg N/ha. In farmers' crops in 1996/97, the highest amount of maize grain (kg) produced for every kg of applied N averaged across the sites was only 3.8 kg, and 12.4 kg in researcher- managed crops. Corresponding values for 1997/98 were 8.9 kg, and 16.0 kg. During 1996/97, it was uneconomic to apply any N at 46% of the sites. In 1997/98, modest economic gains were realised by applying N at up to 100 kg N/ha. The low efficiency of N use demonstrated in this study emphasises the need to develop and use technology and management that will allow farmers to get better returns from N fertilizer on maize.
English
92-9146-065-6
Application rates
Crop management
Fertilizer application
Maize
Research projects
Small farms
Subhumid zones
Zimbabwe
Zea mays
Nitrogen fertilizers
CIMMYT University of Zimbabwe
Low efficiency of nitrogen use by maize on smallholder farms in sub-humid Zimbabwe - Addis Ababa (Ethiopia) CIMMYT|EARO : 1999 - p. 278-281 - Printed
Nitrogen (N) is the major nutrient limiting maize production in Zimbabwe. Surprisingly, little information is available about the maize yield response to N that smallholder farmers obtain on their fields under their own management. On-farm trials were conducted in five sub- humid smallholder areas of northern Zimbabwe during 1996/97 and 1997/98 to establish the response of maize to N. N fertilizer, at rates from zero to 125 kg N/ha (at 25 kg intervals), was applied to farmers' maize crops and to researcher-managed crops planted on farmers' fields. In twelve researcher-managed trials, three maize genotypes: SC401 (short season hybrid), SC601 (medium maturity hybrid) and ZM607 (an open- pollinated experimental population) were used. In 22 farmers' maize crops, N was applied by the farmer to the crop selected by the farmer using the farmers' normal methods and timing. During the very wet 1996/97 season, maize yields in the researcher-managed trials averaged 708 kg/ha without fertilizer and up to 2261 kg/ha with 125 kg N/ha, and from 506 kg/ha without fertilizer up to 1076 kg/ha with 125 kg N/ha in the farmers' crops. In 1997/98, low to medium rainfall led to higher yields. Maize yields in 1997/98 averaged 1205 kg/ha without fertilizer up to 3199 kg/ha with 125 kg N/ha in researcher managed crops, while those in farmers' fields averaged 1096 kg/ha without fertilizer and up to 2210 kg/ha with 125 kg N/ha. In farmers' crops in 1996/97, the highest amount of maize grain (kg) produced for every kg of applied N averaged across the sites was only 3.8 kg, and 12.4 kg in researcher- managed crops. Corresponding values for 1997/98 were 8.9 kg, and 16.0 kg. During 1996/97, it was uneconomic to apply any N at 46% of the sites. In 1997/98, modest economic gains were realised by applying N at up to 100 kg N/ha. The low efficiency of N use demonstrated in this study emphasises the need to develop and use technology and management that will allow farmers to get better returns from N fertilizer on maize.
English
92-9146-065-6
Application rates
Crop management
Fertilizer application
Maize
Research projects
Small farms
Subhumid zones
Zimbabwe
Zea mays
Nitrogen fertilizers
CIMMYT University of Zimbabwe