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Articles by S. Umar
Total Records ( 2 ) for S. Umar
  S. Mustapha , N. Voncir and S. Umar
  A study was conducted to determine the content and distribution of nitrogen forms in some soils of Akko Local Government Area (LGA) of Gombe State, Nigeria. A total of 60 composite soil samples were collected from 0-15 and 15-30 cm depths from purposively selected representative locations in the study area and analyzed using standard procedures. Results obtained showed that the soils were generally low in nitrogen, with organic nitrogen accounting for about 72.8% of the total nitrogen in the soils. The nitrogen forms followed the trend: total nitrogen>total organic nitrogen >NH4-N>NO3¯-N>NO2¯-N in content, while each of the nitrogen forms was more or less uniformly distributed in the study area. Owing to the low available nitrogen content in the soil (<12% of the total N), it is recommended that supplementary nitrogen application and improvement of the drainage conditions of all the soils be employed to improve the nitrogen status of the soils.
  S. Mustapha , N. Voncir , S. Umar and N.A. Abdulhamid
  This study has been conducted to assess the status and distribution of available Zinc (Zn), Copper (Cu), Iron (Fe) and Manganese (Mn) in soils of Akko Local Government Area (LGA), Gombe State, Nigeria. Sixty composite soil samples were collected from 0-15 and 15-30 cm depths from 15 purposively selected representative locations in the LGA and analyzed in the laboratory using standard procedures. Results obtained showed that the soils were generally clayey to sandy clay loams, slightly to moderately acid (pH range = 5.77 -6.5; mean = 6.1), low in organic carbon (mean = 0.83 g kg-1) and low to medium in exchangeable bases. Zinc was generally ‘low’ in all the locations (range = 0.13 to 0.37; mean = 0.22 mg kg-1), Cu ranged from ‘low’ (66.7%) to ‘medium’ (33.3%) while Fe (mean = 10.80 mg kg-1) and Mn (mean = 34.0 mg kg-1) were generally ‘high’ in content. Depth significantly (p<0.05) influenced the distribution of all the micronutrients studied except Fe that did not significantly vary with depth. For sustainable crop production, it is recommended that the pH be improved to near neutral. Crops grown in all the locations will benefit from Zn and organic matter application while areas identified ‘low’ for Cu should have Cu included in their fertilization programme.
 
 
 
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