Organic matter and humus characteristics of some volcanic ash soils of South western Tanzania

dc.creatorMsanya, B. M.
dc.creatorOtsuka, H.
dc.creatorAraki, S.
dc.creatorFujitake, N.
dc.date2017-12-18T10:53:35Z
dc.date2017-12-18T10:53:35Z
dc.date2010
dc.date.accessioned2022-10-25T08:50:53Z
dc.date.available2022-10-25T08:50:53Z
dc.descriptionEnhancing Dissemination of Soil and Water Research Outputs of SADC Universities
dc.descriptionThis study was done on soils developed from volcanic parent materials including pumice and ashes originating from various volcanoes in and around the Rift Valley of South Western Tanzania. The soil moisture and temperature regimes in the area are udic and isothermic respectively. One pedon close to Lake Nyasa (Mwaya) had aquic SMR and isohyperthermic STR. Soil OC content varied widely among and within pedons, with surface horizons generally having higher values (high to very high). N levels also varied similarly and correlated very well with OC. C:N ratios were very variable and increased with increasing OC. Based on the distribution of OC, N, C:N ratios and the relationship among these parameters, the Tanzanian volcanic ash soils compare quite well with known Japanese volcanic ash soils, although the absolute values of OC were much higher for Japanese than for Tanzanian soils. Results on humic acid studies indicate that the soils predominantly contain A type humic acids particularly in the surface A horizon, buried A, AB and BA horizons. These horizons are characteristically humusrich with intense dark colors. UV-VIS absorption spectra revealed in some soils the presence of Pg fraction with absorption bands around (280), 450, 570 and 615 nm, which are normally associated with the presence of dihydroxyperylenequinone (DHPQ) nuclei responsible for the absorption bands at those wavelengths. On the basis of ∆log K, RF, HE, PQ values and the UVVIS absorption spectra, the characteristics of HAs of the Tanzanian volcanic ash soils compare very well with Japanese volcanic soils
dc.formatapplication/pdf
dc.identifierhttps://www.suaire.sua.ac.tz/handle/123456789/1933
dc.identifier.urihttp://hdl.handle.net/123456789/90757
dc.languageen
dc.publisherSADC Project
dc.subjectOrganic matter
dc.subjectHumus characteristics
dc.subjectVolcanic ash soils
dc.subjectTanzania
dc.titleOrganic matter and humus characteristics of some volcanic ash soils of South western Tanzania
dc.typeWorkshop Presentation

Files