Articles, Conference and Workshop Papers Collection
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Browsing Articles, Conference and Workshop Papers Collection by Author "Amuri, N."
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Item Evaluation of the soil fertility status in relation to crop nutritive quality in the selected physiographic units of Mbeya Region, Tanzania(RUFORUM, 2010-09) Amuri, N.; Semu, E.; Msanya, B. M.; Mhoro, L.; Anthony, J. M.This study is assessing soil fertility status in Mbeya region of Tanzania in terms of adequacy for crop growth and crop nutrient status in terms of human nutrition. It will examine levels of macro and micronutrient. The study has just been initiated and will run for two years.Item Pedological characteristics and implication on soil fertility of selected soils of Mbeya Region, Tanzania(RUFORUM, 2012-09) Amuri, N.; Mhoro, L.; Munishi, J. A.; Msanya, B. M.; Semu, E.; Malley, Z.Understanding the soil origin and its fertility in a given climatic conditions is important for efficient and sustainable utilization of soils. The composition of parent material determines the mineral nutrient content (Nube and Voortman, 2006), and sorption of nutrients, other chemicals and soil organic matter. A recent study in China demonstrated that available Fe and Zn in Xichang city soils differed depending on the nature of the parent rock (Zhang et al., 2012). Time is also essential in determining the stage of weathering, and hence soil properties. The soils of the surveyed areas are derived from volcanic tephra deposits of which are reported to be from relatively old (Upper Miocene to Lower Pleistocene Kitulo and Ngozi volcanoes) to most recent eruptions (Middle Pleistocene to Holocene Rungwe and Kyejo Volcano) (Fontijn et al., 2010). Information on the differences in chemical and other characteristics of the soils derived from these chronologically variable deposits of the area is limited. Mbeya region is among the four regions of Southern Highlands of Tanzania with high agricultural production, supplying major staple food in the country. However, crop yields are still low despite use of NPK fertilizers, contributing to food insecurity in Tanzania. Copper and Zn deficiencies were reported in this area’s volcanic soils about three decades ago, which was associated with nutrient mining (Kamasho, 1980). Yet, to date there is no follow-up studies on the status of these micronutrients in soils. Therefore, there is a need to determine the properties of soils of Mbeya region in relation to their origin and genesis. Mineral malnutrition is also wide spread and it is estimated that about 66% of world population is Fe deficient, over 30% is Zn deficient, 30% is iodine deficient and 15% is selenium deficient (White and Broadley, 2009). In Tanzania about 65% of children under 5 years of age are iron deficient (Fortifying African’s Future, 2009), 58.2% of pregnant women are anemic and 23% of the population are at risk of Zn deficiency (TFNC, 2009). These nutritional health problems can be attributed to low soil mineral content and/or availability to crops (Welch and Graham, 2002). Adequate levels of essential minerals in food crops to satisfy human health requirement is referred to as crop nutritive quality. One way to curb mineral malnutrition is fortification of some staple food with these essential minerals. However, food fortification cannot be expected to reach all populations deficient in essential micronutrients, especially in developing countries, and have challenge of low bioavailability (Hurrell, 1997; Mehasho, 2006). Therefore, there is a need to investigate, systematically, the relationship between soil nutrient contents (both macro- and micro-nutrients) and crop quality as might be related to the potential for agronomic biofortification to improve human nutrition and health. This study was therefore conducted as a contribution to efforts by national and international programs and strategies to attain not only high yields but also nutritional health for poverty alleviation. Therefore, the objective of this study was to determine and assess the pedologicalcharacteristics of soils and their influence on soil fertility and crop quality in selected physiographic units of Mbeya region. Specifically, i) to determine the morphological and physico-chemical characteristics of the soils ii) to determine the mineralogical composition of the soils iii) to determine the extent of weathering, and iv) to determine the implication of soil characteristics on nutrient availability, agricultural productivity and crop nutritive quality.Item Pedological characterization of typical soils of Dodoma Capital City District, Tanzania: soil morphology, physico-chemical properties, classification and soil fertility trends(Isaac Scientific Publishing, 2018-11-04) Msanya, B. M.; Mwasyika, T. A.; Amuri, N.; Semu, E.; Mhoro, L.Pedolological characterization was done in Dodoma Capital City District, Tanzania. Three soil profiles developed from in-situ weathering of granic rocks and designated as HIS-P1, HIS- P2 and HIS-P3 were described. Fifteen samples were taken from genetic horizons and analyzed for physical and chemical characteristics. The soils were generally very deep, with varying textures. Whereas profile HIS-P2 was dominantly loamy, profiles HIS-P1 and HIS-P3 were both clayey but the latter had heavy clay type. In profile HIS-P1, clay eluviation-illuviation was a dominant pedogenic process manifested by presence of clay cutans in the subsoil. Profile HIS-P2 displayed redoximorphic features due to fluctuating water table. Shrinking and swelling, and argilli-pedoturbation were typical pedogenic processes in profile HIS-P3. Profile HIS-P1 had more developed structure (subangular blocky) followed by HIS-P3 and lastly profile HIS-P2 which was structureless massive breaking into weak subangular blocks. Whereas topsoil bulk density values of the soils were within acceptable range, subsoil BD values are likely to cause problems of root penetration particularly for deep rooted crops. Profiles HIS-P1 and HIS-P3 may present limitations to crop growth due to high pH values (> 7.5) in the subsoil which may limit availability of plant nutrients e.g. phosphorus. Organic carbon and nitrogen were generally low and very low in all profiles with most values being < 1.25% and < 0.10%, respectively. Availabe P values were low to very low (< 7 mg/kg) throughout the three profiles. Topsoil base saturation values were high (> 50%) in profiles HIS-P1 and HIS-P2 but very high throughout proflie HIS-P3 (83 - 118%). Zn and Fe levels were rated as inadequate for crop production. According to USDA Soil Taxonomy, the soils were classified as Typic Rhodustults (HIS- P1), Fluventic Dystrustepts (HIS-P2) and Chromic Calcitorrerts (HIS-P3) corresponding to Haplic Cutanic Acrisols, Haplic Cambisols and Calcic Mazic Vertisols in the WRB for Soil Resources. The three soils had different physico-chemical properties, hence the need to characterize soils before fertilizer recommendations is met.Item Soil morphology, physico-chemical properties and classification of typical soils of Mwala district, Kenya(International Journal of Plant & Soil Science, 2014-10) Karuma, A. N.; Gachene, K.; Charles, K.; Msanya, B. M.; Mtakwa, P. W.; Amuri, N.; Gicheru, P. T.A soil profile representative of typical soils of Mwala District, Kenya, was dug to study its morphology, soil physico-chemical characteristics and to classify it using two internationally known soil classification systems. Disturbed and undisturbed soil samples were taken from designated pedogenic horizons for physical and chemical analysis in the laboratory. Soil morphological observations revealed that the pedon is well drained and very deep with dark brown to dark yellowish brown topsoil overlying brown to strong brown sandy clay loam to sandy clay subsoil. Clay eluviations - illuviation is a dominant process influencing soil formation in the study area as indicated by the clay gradient between the eluvial and illuvial horizons and the presence of clay cutans in the subsoil. The soil is characterized by weak fine subangular blocky throughout its pedon depth. Laboratory analysis indicates that the soil is very strongly acid (pH 4.6–5.0) throughout the profile, has very low N (<0.1%) and low OC (0.6-1.25%). The pedon has low CEC (6.0-12.0 cmol (+) kg -1 ) and low base saturation (<50%). Available P is rated as high (>20mg kg -1 ) in the topsoil -1 while it is low (7-20mg kg ) in the major part of the subsoil. Using field and laboratory analytical data, the representative pedon was classified to the subgroup level of the USDA Soil Taxonomy as Typic Haplustults and to Tier-2 of WRB as Haplic Cutanic Acrisols (Humic, Hyperdystric, Endosiltic). The general fertility of the soils of the area is discussed highlighting their potentials and constraints.