6 Records out of 22207 Records

Potential role of biochar in water management in rainfed agriculture

Author: Flavia, Namagembe

Awarding University: University of Edinburgh, Scotland

Level : MSc

Year: 2012

Holding Libraries: Institute of Commonwealth Studies Library ;

Subject Terms: Biochar ; Sugarcane ; Saccharum officinarum ; Bamboo ; Arundinaria alpina ; Soils ;

Abstract:

The economies of the three East African region (Uganda, Kenya and Tanzania), which is the region of interest in this study still rely largely on rainfed agriculture accounting to approximately 80% of the total agricultural production. With the increasing threats from climate variability, the region is prone to extreme conditions of drought and floods. Inadequate soil moisture and low soil fertility have been the challenges facing rainfed agriculture in the region and several approaches have been employed to help manage agricultural water sustainably. Previous studies indicate that incorporation of biochar into sandy soil improves its water retention capacity. This study demonstrates how addition of biochar produced from different feedstock biomass of sugarcane (Saccharum officinarum Linn) trash and bamboo (Arundinaria alpina) leaves and branches, all obtained from the region using both the laboratory controlled equipment at 350 oC, 450 oC and 550 oC and a traditional stove, to sandy soil has the potential improve the soil?s water holding capacity. This way, biochar can thus play a significant role in water management in agriculture in the East African region with the aim of reducing agricultural input and maximizing crop yields. For the traditional stove, it was difficult to control the temperature while producing the biochar but the highest steady temperature reached during production was recorded. The hydrologic properties including water holding capacity and hydrophobicity of sandy soil, biochars and soil-biochar mixtures were measured using the gravimetric method and the molarity of ethanol drop test respectively. Additionally, porosity was determined using the mercury porosimetry method in order to compare the pore size distribution of the biochars with their hydrologic properties. Biochars produced from different feedstock biomass under different production conditions varied in their hydrologic behavior and influenced soil?s hydrologic properties differently when added to it. The study demonstrates water retention increases in a sandy soil after addition of 2, 5 and 7 weight % biochar (20, 50, and 70 t ha-1 respectively).

Mass propagation of bamboo and its adaptability to waste water gardens

Author: Murage, Hunja

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : PhD

Year: 2009

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Bamboo ; Plant reproduction ; Water treatment ;

Abstract:

Mass Propagation of Bamboo, and its Adaptability to Waste Water Gardens Unregulated and inappropriate disposal of wastewater poses serious pollution problems in many parts ofthe developing World. However, reuse of wastewater may help to ameliorate global water shortages, especially in developing nations where facilities for safe disposal of wastewater do not exist. Some bamboo species grow more rapidly than timber species and have numerous actual and potential applications for environmental conservation and income generation. In view of these attributes, bamboo was chosen for use in the present study of the potential utilisation of wastewater to improve water and nutrient supplies, while providing an environmentally compatible method for wastewater disposal and a fast-growing, non-timber source of woody material for subsistence farmers As the extremely long vegetative period before flowering occurs in many species limits seed supplies, it is vital to develop effective methods for mass propagation of bamboo to enable its widespread adoption by subsistence farmers in East Africa. Seven potentially important species were used in studies intended to develop suitable micropropagation procedures: these were Dendrocalamus membranaceus, Dendrocalamus yunnanicus, Dendrocalamus strictus, Phyllostachys heterociada, Oxytenanthera abyssinica, Phyllostachys pubescene and Dendrocalamus giganteus. Multiplication rates differed between species (P<O.OOI) and these difference became apparent within five months of establishing the cultures. D. yunnanicus was the most promising in terms of multiplication rate, easily outperforming all other species (P<O.OO 1), by increasing to 3,500 plantlets within eight months. species (Dendrocalamus giganteus, Bambusa vulgaris and B. nutans) were grown in 100 tanks in a factorial experiment under field conditions. Sewage effluent or clean water was applied daily according to the treatment involved. A second experiment contained 339 younger plants irrigated with three sources of water, including industrial wastewater. Subsequent analysis revealed that the wastewater did not contain toxic concentrations of nutrients or trace metals. Weekly and diurnal measurements of net photosynthesis, transpiration rate and stomatal conductance were made over a nine month period, while non-destructive measurements of plant height, collar diameter, number of leaves and leaf area were made over a 15 month period. Destructive harvests after 0, 9 and 15 months of treatment were used to determine leaf and stem fresh and dry weights. When averaged over all species, irrigation with wastewater increased stem fresh and dry weight plant' by 30-40 % relative to plants receiving clean water (P<0.05), with B. vulgaris and B. nutans performing better than D. giganteus. A significant water*time interaction was apparent for plant height, branch number, leaf area plant' and biomass production for all species; values were greater for plants irrigated with wastewater than in those receiving clean water. Volumetric soil moisture content did not differ significantly between the clean and wastewater treatments between March and November 2006, but differed between the two measurement depths (20 and 60 em; P<O.OO 1). The gas exchange and SPAD values (an indirect measure of chlorophyll concentration) revealed several significant effects. SP AD values varied with time (P<O.OO 1), but not between species, and were greater in plants irrigated with wastewater than in those receiving clean water (P<O.OO 1). Stomatal conductance, transpiration and net photosynthesis all showed significant effects of species, irrigation treatment, time and leaf position in the canopy (P<0.05). Instantaneous transpiration efficiency (ITE) was greater in plants irrigated with wastewater than in those receiving clean water (P<0.05). Elemental analysis showed that the concentrations of trace metal nutrients in the wastewater supplies used in both experiments were not sufficiently

Propagation for maximum production of planting material and water use studies for giant bamboo dendrocalamus giganteus

Author: Mutune, Adelaide Ndunge

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2006

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Bamboo ; Giant bamboo USE Dendrocalamus giganteus ; Dendrocalamus giganteus ; Plant reproduction ;

Abstract:

Giant bamboo (Dendrocalamus giganteus) is one of the fastest growing bamboo species in the world and is being popularised to supplement the growing demand for wood products in Kenya. The species, however, roots poorly under vegetative propagation because and cuttings die excessively after sprouting mainly attributed to fungal infestation. This study was aimed at improving the rooting and survival percentages of D. giganteus cuttings. Moreover, provision of pathogen-free planting material through in vitro propagation was explored. Exotic to Kenya, 0: giganteus water usage and adaptability must be established hence the water experiments in the study.To promote rooting, auxins (Naphthalene acetic acid (NAA) and Indolebutyric acid (lSA) at concentrations of 20, 80, 140 and 200 mgr1 each) were applied. Auxin application significantly promoted rooting (p<0.01) with NAA performing better than ISA. NAA 200 mgr1 had the highest rooting (55%) while the controls had only 2.5%. Isolation of fungi from D. giganteus dying shoots and cuttings yielded Fusarium genus which was sensitive to Ridomil? 80% and 90% and CuOCI 20% and 70%. The effectiveness of these fungicides was significantly (p<0.05) reduced by dampness hence the conclusion that dampness is important in D. giganteus propagation. In vitro propagation of D. giganteus was in full Murashige and Skoog (MS, 1962) supplemented with a wide range of hormones, 25 0 C and 16 h photoperiod. NAA 5.2 JM + SAP 8.8 JM had a significantly high shoot production (50%) and the fastest growing shoots while NAA 41.6 JM + SAP 8.8 JM had a significantly (p<0.05) high mean shoot number (3). Soil moisture of 0.15 to 0.4 cm3cm-3 (water/soil) on D. giganteus established seedlings had a significant (p<0.05) effect on assimilation and transpiration rates, growth rates and dry matter contents but not on Water Use Efficiency (highest WUE value was 11 JMm-2s- The higher soil moisture contents had higher values. These preliminary results show that D. giganteus seedlings can withstand low moisture conditions without excessively reducing the processes. These results give a strong background for expanding D. giganteus in Kenya because a reasonable success rate is attainable and its water demand satiable in many regions, of Kenya.

Flexural behaviour of large scale concrete elements reinforced with bamboo

Author: Maritim, Nelson Kipkemboi

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2004

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Civil engineering ; Concrete ; Bamboo ;

Abstract:

This research study is on bamboo culms as an alternative material for concrete reinforcement in low cost housing. In this research the commonly found bamboo species in Kenya Arundiraria Alpina was used to reinforce concrete beams, which were then subjected to flexural test. Other tests like tensile, compression, shear, pull-out test of bamboo and steel in concrete were also done in order to understand the basic properties of bamboo as a reinforcement material. Various tests such as compression, tension splitting and flexural testing prisms were also conducted on the concrete, in order to ensure that the concrete used met the required standard. The strength tests of bamboo obtained and those of previous investigations carried out by other researchers depict bamboo to be a fairly strong material that can be used as a substitute for steel reinforcement. The mean tensile strength of seasoned bamboo is 197.61 Nzmm' and 251.28 Nzmm? for bamboo with and without nodes respectively. The average composite strength of bamboo reinforced concrete beams is 105.5 Nzmm- at 28 days, which is about a half the actual tensile strength of seasoned bamboo. The average Elastic modulus of bamboo is 23.31kN/mm2 for seasoned bamboo and the mean interfacial bond strength of quarter bamboo in concrete is 1.99 Nzmm? at 28 days, which is about 25 % that of structural steel in concrete, which was determined as 7.78 Nzmm- at 28 days. The results show that splitting of bamboo reinforcement into different shapes ???improves the interfacial bond because the newly exposed surface is rougher than the outer surface. Also, it is noted that arranging bamboo reinforcement splits with their concave facing upwards (HBU and QB) enhances bamboo reinforcement stiffness than those with their concave facing downwards (HBD) and whole bamboo culm (FB). This resulted to higher composite strength in HBU and QB reinforced concrete beams than those ofFB and HBD reinforced concrete beams. It is concluded that the use of splitted longitudinal aligned continuous bamboo in the reinforcement of concrete gives rise to significant improvement of the mechanical properties of concrete. The recommendation is made that bamboo pieces with an average width of 20mm and with their concave part facing upwards, could be used to reinforce concrete beams.

Mechanical properties of bamboo (Bambusa vulgaris) grown in Muguga, Kenya

Author: Mbuge, Duncan Onyango

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 2000

Holding Libraries: University of Nairobi Upper Kabete Library ;

Subject Terms: Bamboo ; Bambusa vulgaris ; Muguga, Kenya ; Forestry ;

Abstract:

This research projcct investigated the tensile, bending and compressive strength of a species of bamboo called Bambusa vulgaris, in all effort to contribute towards the development of a code of design using bamboo. The density of the of B. Vulgaris was found to be 590 kg/m' (oven dry). The tensile strength was found to be 94.3 MPa with nodes and 117.9 MPa without nodes. The compressive strength was 49.9 MPa with nodes and 56.7 MPa without nodes, bending strength was 107.0 MPa with nodes and 13 7.7 MPawithout nodes and the modulus of elasticity in tension was 3002.2 MPa with nodes and 3594.0 MPa without nodes. The Modulus of Elasticity in compression was 10,405.3 MPa without nodes and 7,268.1 MPa with nodes. The nodes were found to have a significant effect in lowering the tensile and bending strength of bamboo. The compressive strength was not affected by the presence or absence of nodes.

Strength characteristics of bamboo : structural application in bamboo-reinforced concrete.

Author: Mwaura, Stephen Mburu

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 1996

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Bamboo ; Concrete ; Building materials ;

Abstract:

ABSTRACT NOT AVAILABLE