Browsing by Author "Moberg, J. P."

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Pedological and edaphological properties of the soils of two soil associations in the Morogoro area, Tanzania
(Trop. Agric. (Trinidad), 1982) Moberg, J. P.; Msanya, B. M.; Kilasara, M.
Pedological and edaphological properties of two soil associations forming a continuum from the Uluguru \mountain ranges to the Mindu mountain in the Morogoro area, Tanzania, have been investigated. The general /eatures of the area, including climate, geology and vegetation are discussed as is the movement of soluble salts on the slopes and its effects on soil composition. The investigation shows that there is a close connection between the three soil forming factors, climate, parent material, and relief and the mineral composition of the soils and their edaphological properties. This means that a thorough understanding of the soil forming factors and the soil development processes provides a key to land use evaluation of an area like this, where soil data often are lacking.
Physico-chemical finding related to the resilience of different soils in the semi-arid parts of Tanzania and their implications on sustainable agriculture
(1999) Moberg, J. P.; Szilas, C.; Midtgaard, T.
As part of an interdisciplinary study on Sustainable Agriculture in Semiarid Areq.s (SASA) in south-central Tanzania, soils from five different locations were investigatedfor their mineralogical composition and physico-chemical characteristics in order to determine their resilience in relation to land use. The results of the inves~igation show tha,t soils developed in such areas on sediments of Holocene age to a certain extent are capable of retaining their chemicalfertiliry as long as low intensity agriculture is being practised. The content ofweatherable:minerals .in the quite silt-rich soils is so large that the weathering taking place, seems sufficient under the prevailing semiarid conditions to ensure adequate supply of plant nutrients for low intensity crop production with the exception of N, P and S. The sand and silt fractions contained substantial amounts of mica and plagioclase and smaller amounts of hornblende/pyroxene. In addition to kaolinite and iron oxides, the clay fraction contains illite and smaller amounts of other 2:1 layer silicate clay minerals. The extractable amount of P is low, although the P-retention is expected to be limited, as the content of P-fixing components is limited. In contrast, the soils in the area formed in situs on metamorphic rocks contain onlyquar:tz andyery small amounts of microcline and muscovite in the s{mdfraction. The siltfraction is high in quartz too besides having some kaolinite and gibbsite, The clay fraction of these soils is composed mainly of kaolinite with smaller amounts of Fe-ox ides and illite, Chemically, the capacity of these soils is so low that they will not to any degree release any plant nutrients by weatHering. The extractable P is also low in these soils, as the P present may be considered to be ,stronglyretained due to the mineralogical composition of these soils. Due to their content of stable micropeds the strongly weathered soils developed in situs are more porous than the less strongly weathered soils developed on the Holocene sediments. However, their available water holding capacity may be expected to be lower than that of the soils developed on the sediments, as such soils normally have a limited number of pores in which plant available water is stored