Variations in selected soil physical properties with landforms and slope within an inland valley ecosystem in Ashanti region of Ghana

Sunday E. Obalum, John C. Nwite, James Oppong, Charles A. Igwe and Toshiyuki Wakatsuki
Additional contact information
Sunday E. Obalum: Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, Nigeria
John C. Nwite: Department of Crop Production Technology, Federal College of Agriculture, Ishiagu, Nigeria
James Oppong: CSIR, Soil Research Institute, Kumasi, Ghana
Charles A. Igwe: Department of Soil Science, Faculty of Agriculture, University of Nigeria, Nsukka, Nigeria
Toshiyuki Wakatsuki: School of Agriculture, Kinki University, Nara, Japan$2

Soil and Water Research, 2011, vol. 6, issue 2, 73-82

Abstract: One peculiar feature of the inland valleys abundant in West Africa is their site-specific hydrology, underlain mainly by the prevailing landforms and topography. Development and management of these land resources under the increasingly popular sawah (a system of bunded, puddled and levelled rice field with facilities for irrigation and drainage) technology is a promising opportunity for enhancing rice (Oryza sativa L.) production in the region. Information on the variations in selected soil physical properties as influenced by the prevailing landforms may serve as a useful guide in site selection. This is of practical importance since majority of the inland valleys are potentially unsuitable for sawah development and most farmers in the region are of low technical level. Three landforms (river levee, elevated area and depressed area) were identified within a sawah field located in an inland valley at Ahafo Ano South District of Ghana. Each of these landforms was topsoil-sampled along on identified gradient (top, mid and bottom slope positions). Parameters determined included particle size distribution, bulk density, total porosity and field moisture content. The soil is predominantly clayey. There were no variations in the particle size distribution among the slope positions in the river levee. Overall, the river levee had lower silt content than the elevated and the depressed landforms. The bulk density, total porosity, and gravimetric moisture content indicated relative improvements only in the depressed area in the order, bottom > mid > top slope. Irrespective of slope position, the three landforms differed in these parameters in the order, depressed > river levee > elevated. The sand fraction impacted negatively on the silt fraction and bulk density of the soil, both of which controlled the soil moisture status. Despite the fairly low silt content of the soil, the silt fraction strongly influenced the gravimetric moisture content (R2 = 0.80). So too did the soil bulk density on the gravimetric moisture content (R2 = 0.90). It is concluded that: (1) since the landforms more prominently influenced the measured parameters than the slope positions, the former should take pre-eminence over the latter in soil suitability judgment; (2) with respect to moisture retention, variations in silt fraction and bulk density of this and other clayey inland-valley soils should be used as guide in site selection for sawah development.

Keywords: bulk density; landscape position; moisture content; particle size distribution; sawah rice field; total porosity (search for similar items in EconPapers)
Date: 2011
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (2)

Downloads: (external link)
http://swr.agriculturejournals.cz/doi/10.17221/17/2010-SWR.html (text/html)
http://swr.agriculturejournals.cz/doi/10.17221/17/2010-SWR.pdf (application/pdf)
free of charge

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:caa:jnlswr:v:6:y:2011:i:2:id:17-2010-swr

DOI: 10.17221/17/2010-SWR

Access Statistics for this article

Soil and Water Research is currently edited by Ing. Markéta Knížková, (Executive Editor)

More articles in Soil and Water Research from Czech Academy of Agricultural Sciences
Bibliographic data for series maintained by Ivo Andrle ().