Table of Contents
ISRN Agronomy
Volume 2012, Article ID 597216, 10 pages
Research Article

Effects of Organic and Inorganic Materials on Soil Acidity and Phosphorus Availability in a Soil Incubation Study

1Department of Horticulture, Kabianga University College, P.O. Box 2030, Kericho, Kenya
2Department of Soil Science, Moi University, P.O. Box 1125, Eldoret, Kenya

Received 5 April 2012; Accepted 10 May 2012

Academic Editors: R. Burt, T. E. Fenton, and J. Hatfield

Copyright © 2012 P. A. Opala et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We tested the effects of two organic materials (OMs) of varying chemical characteristics that is, farmyard manure (FYM) and Tithonia diversifolia (tithonia), when applied alone or in combination with three inorganic P sources, that is, triple superphosphate (TSP), Minjingu phosphate rock (MPR), and Busumbu phosphate rock (BPR) on soil pH, exchangeable acidity, exchangeable Al, and P availability in an incubation study. FYM and tithonia increased the soil pH and reduced the exchangeable acidity and Al in the short term, but the inorganic P sources did not significantly affect these parameters. The effectiveness of the inorganic P sources in increasing P availability followed the order, TSP > MPR > BPR, while among the OMs, FYM was more effective than tithonia. There was no evidence of synergism in terms of increased available P when organic and inorganic P sources were combined. The combination of OMs with inorganic P fertilizers may, however, have other benefits associated with integrated soil fertility management.