Browsing by Author "Araki, S."

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Land use and land evaluation Systems Research Project
(Sokoine University of Agriculture, 1993) Kimaro, D. N.; Msanya, B. M.; Maggogo, J. P.; Msaky, J. J.; Araki, S.; Hirai, H.
Organic matter and humus characteristics of some volcanic ash soils of South western Tanzania
(SADC Project, 2010) Msanya, B. M.; Otsuka, H.; Araki, S.; Fujitake, N.
This 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
Pedon characteristics and their implications for land management in two villages of Mbinga district,Tanzania
(Tanzania Journal of Agricultural Sciences, 1998) Msanya, B. M.; Kimaro, D. N.; Araki, S.
A land resources study was carried out in Lupilo and Tukuzi villages in Mbinga District. Two pedons representing the villages were selected for the study to obtain data that are important for land management. Standard soil and land resources survey procedures were employed. The results show that the soils are very deep, well drained, red and dark reddish brown sandy clays to clays and classify as Haplic Acrisol (Isohyperthermic, very deep, kaolinitic, Typic Rhodustuli) at Lupilo and Ferric Acrisol (lsohyperthermic, very deep. kaolinitic, Ustic Haplohumult) at Tukuzi. The structure is generally poor for the two pedons. Bulk density values are low throughout Tukuzipedon. Both pedons have medium available water capacity and generally low soil fertility. The clay mineralogical composition is dominantly kaolinitic with accessory amounts of sesquioxides. These characteristics are associated with poor soil conditions. The study shows that the two pedons represent fragile ecosystems that require careful management. Due to poor chemical, mineralogical and physical characteristics, the study recommends areas offurther research. The commonly used tie-ridge (Ngolo) cultivation system should be studied further to find out its contribution to soil fertility, The use of rock phosphate as a P-fertilizer and as a possible liming material should be further investigated.