Response of bread wheat to increasing mustard meal nitrogen application on pellic Vertisol and utric Nitosol
Mustard seed meal was evaluated on the field as source of nitrogen for bread wheat on Pellic Vertisol and Eutric Nitosol in a split plot design with three replications. Highly significant yield increases were obtained due to mustard meal nitrogen rates during all the experimental periods on the Vertisol. The increase in the grain yields of wheat was linearly related to the mustard meal nitrogen rates (r=0.98 and 0.96 for fresh and decayed meal, respectively) and varied from two to ten fold of the control. On the Nitosol, significant effect was obtained only in one crop season. Greenhouse experiment on the nitrogen uptake from the mustard meal using 15N showed significant difference on both soil types. On the Vertisol the per cent nitrogen derived from the meal and per cent nitrogen use efficiency varied from 18 to 40 and from 18 to 62%, respectively. On the Nitosol, these values varied from 25 to 71 and from 43 to 62%, respectively. Application and incorporation of the mustard seed meal into the soil 20B25 days before planting minimised the toxicity of the meal on seed germination and seedling growth.
SINET: Ethiopian Journal of Science Vol. 23, No. 1 (June 2000), pp. 53-66
Key words/phrases: Eutric Nitosol, mustard seed meal, nitrogen use efficiency, Pellic Vertisol, wheat