Phosphorus (P) is an essential plant nutrient and is one of the most critical elements influencing crop production throughout the world. Phosphorus deficiency is widespread in most soils of northern Ghana, and ferruginous nodules contained in some soils in the region accentuate the deficiency problem because they act as P sinks. This research focuses on P fertility status of soils in landscapes common to northern Ghana. Three sites were selected for the study and were referred to as sites 1, 2 and 3. Soils in a catenary sequence from site 1 were sampled for detailed P distributions in profiles, and surface soils from the upper, mid and lower slope positions of the other landscapes (sites 2 and 3) were used. The nature of P in the soil fines and ferruginous nodules was investigated using a modified Hedley fractionation procedure. The objective was to quantify the labile and non-labile inorganic P (Pi) and organic P (Po) in relation to pedogenic weathering processes at different slope positions at site 1. A secondary objective was to assess the P distribution in the landscapes at sites 2 and 3. The largest P fraction in both soil fines and nodules at each site was resistant non-labile P forms. Primary P (Ca-P) decreased with depth in the profile at the upper slope position but it occurred in greater quantities in C horizons of the lower slope soils. Phosphorus sorption capacity of the soil fines and nodules was determined to predict the behaviour of P fertilizers in the soils. Phosphorus sorption by the soil fines increased to a maximum in the B horizon of each profile and a t-test showed that P sorption was similar in profiles at each slope position. The P sorption capacities of uncrushed ferruginous nodules varied according to their sizes. The small nodules were more reactive and sorbed more P than the larger sizes. Fractionation of P from the nonfertilized and fertilized soils at the end of cropping and anion exchange resin (AER) extraction, revealed that there had been redistribution of P into different fractions. A comparison of P fractions of the nonfertilized soils after the AER extraction with those of the native soil P showed decreases in some native labile and non-labile P fractions. This suggested that these P fractions could be available for plant uptake. Both 50% PAPR and SSP fertilizations increased the labile Pi and NaOH extractable Pi levels in the soils. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-10212004-000448 |
| Date | 01 January 1996 |
| Creators | Abekoe, Mark Kofi |
| Contributors | de Jong, Eeltje |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-10212004-000448 |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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