African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6849

Full Length Research Paper

Soil pH, available P of an ultisol and castor performance as influenced by contrasting tillage methods and wood ash

Nweke, I. A.
  • Nweke, I. A.
  • Department of Soil Science, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria.
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Mbah, C. N.
  • Mbah, C. N.
  • Department of Soil Science and Environmental Management, Ebonyi State University, Abakaliki, Ebonyi State, Nigeria.
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Oweremadu, E. O.
  • Oweremadu, E. O.
  • Faculty of Agriculture, Federal University of Technology, Owerri, Imo State, Nigeria.
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Dambaba, N.
  • Dambaba, N.
  • National Cereal Research Institute, Baddagi, Bida, Niger State, Nigeria.
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Orji, E. C.
  • Orji, E. C.
  • Department of Crop Science and Horticulture, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria.
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Ekesiobi, A. I.
  • Ekesiobi, A. I.
  • Department of Crop Science and Horticulture, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria.
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Nnabuife, E. L. C.
  • Nnabuife, E. L. C.
  • Faculty of Agriculture Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
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  •  Received: 15 December 2016
  •  Accepted: 23 January 2017
  •  Published: 23 February 2017


The effect of tillage methods and rates of wood ash on soil chemical properties and castor bean plant performance was studied in field trial at Abakaliki in three planting seasons. The experiment was a split plot in randomized complete block design with three tillage methods (mound, ridge, flat) and four rates of wood ash (0, 2t, 4 and 6 tha-1) replicated three times. Crop start version 7.2 was used to analyze data collected and mean separation was done using least significant difference (LSD) at 5% alpha level. The results of soil pH and available P showed that tillage method (TM) increased the values of the nutrients in 2nd year, but decreased in the 3rd year planting. The values of these parameters observed in Ridge method was found to be higher when compared to the values of Mound and Flat except for the result of available P in 1st  and 3rd year planting periods. The wood ash (WA) amendment was found to change the soil from slightly acidic in 1st year to alkaline in 2nd year to slightly acidic in 3rd year. The control soil remained acidic throughout the three years of study. The available P obtained from Rd6 consistently gave the highest values among the TM and rates of WA. Tillage methods had no effect on leaf area index (LAI) at 50 days after planting (DAP) and 100 DAP in 1st and 2nd year planting periods, but had significant effect on the parameters in 3rd year planting season. Flat showed highest plant height in 1st and 2nd years but decreased in the 3rd year. While the least value in plant height for the 3 years’ of study was recorded in Mound. The findings from this study has clearly shown that soil application of wood ash and tillage practices has the potential to cause positive and useful changes in the fertility and productivity status of the soil by improving the soil properties and yield component of castor.


Key words:  Ash, available P, castor plant, leaf area, plant height, soil reaction, tillage.