Department of Engineering Sciences and Technology

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Browsing Department of Engineering Sciences and Technology by Author "Asch, F"

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    Effects of Nitrogen and Phosphorus Micro-Doses on Maize Growth and Yield in a Sub-Humid Tropical Climate
    (2018) Saidia, P.S; Rweyemamu, C.L; Asch, F; Semoka, J.M.R; Kimaro, A.A; Germer, J; Graef, F; Lagweni, P; Kahimba, F; Chilagane, E.A
    Inadequate knowledge on fertilizer usage and poor financial resources are among the reasons for low maize productivity under small-scale farming. Fertilizer micro-dosing may increase food production by using low rates which are affordable by most resource poor farmers and have a high investment return. A two-year field experiment was conducted on sandy loam and sandy clay soils being typical representatives of sub-humid tropical agroecological zones. A split-plot design involved di-ammonium phosphate (DAP), Minjingu mazao (MM) and triple super phosphate (TSP) as main plots and fertilizer micro-dose rates of 10 kg N and 5 kg P/ha, 20 kg N and 10 kg P/ha, 40 kg N and 20 kg P/ha, 60 kg N and 30 kg P/ha, recommended rate 80 kg N and 40 kg P ha-1 and control as sub-plots. Phosphate fertilizers that produced highest grain yield were MM (2317 kg/ha), followed by DAP (2173 kg/ha) and TSP (2115 kg/ha). Fertilizer micro dose rates (10 kg N and 5 kg P/ha; 20 kg N and 10 kg P/ha) increased the yield by 90.5 and 136.6% from 1012 kg/ha in control, respectively. Intermediate rates (40 kg N and 20 kg P/ha) and (60 kg N and 30 kg P/ha) produced average grain yields of 2629 and 2647 kg/ha while the recommended rate produced 2601 kg/ha. The highest grain yield was 3910 kg/ha from MM at 40 kg N and 20 kg P/ha. Considering the micro-dose options therefore, MM fertilizer and micro dose rates (10 kg N and 5 kg P/ha) and (20 kg N and 20 kg P/ha) are recommended in these agro-ecological zones.
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    Multi-Disciplinary North-South Collaboration in Participatory Action Research on Food Value Chains: a German-Tanzanian Case Study on Perceptions, Experiences and Challenges
    (Springer, 2018) Graef, F; Mutabazi, K.D; Sieber, S; Asch, F; Makoko, B; Bonatti, M; Brüntrup, M; Gornott, C; Herrmann, L; Herrmann, R; Kaburire, L; Kahimba, F.C; Kimaro, A; Kuntosch, A; König, H.J
    Upgrading local food value chains is a promising approach to invigorating African food systems. This endeavour warrants multi-disciplinary North-South collaboration and partnerships through participatory action research (PAR) to help leverage appropriate upgrading strategies (UPSs) with a focus on local stakeholders. The more disciplines, cultures,and partner institutions that are involved, the more a project will present challenges in terms of communication and coordinating activities. Our aim was to determine the costs and investigate whether PAR with a multi-disciplinary approach was feasible in rural Tanzania with over 600 local stakeholders and more than 100 scientists. This article presents a self-evaluation of the collaboration and communication of project scientists during their research activities. Despite the overall high satisfaction, the more complex and complicated PAR activities required more cooperation, instructions and communication among the project scientists than had been anticipated in this multi-disciplinary, multi-cultural, and multi–institutional context, resulting in greater tension and dissatisfaction. The findings indicate that this type of large multidisciplinary PAR is challenging in terms of flexibility in the planning of research activities, the administration of finances, and cross-cultural communication. Potential avenues to overcome these obstacles include a) more communication on PAR activities across cultures to develop a shared vocabulary; b) developing other modes of shared responsibility for a more horizontal collaboration; and c) more face-to-face cross-cultural activities to overcome cultural, disciplinary and geographical distance.
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    Soil moisture management and fertilizer micro-dosing on yield and land utilization efficiency of inter-cropping maize-pigeon-pea in sub humid Tanzania
    (Elsevier, 2019-07) Saidia, P.S; Rweyemamu, C.L; Semoka, J.M.R; Kimaro, A.A; Germer, J; Asch, F; Kahimba, F.C; Graef, F; Lagweni, P.P
    Principally caused by soil water stress and declining soil fertility, low crop productivity results in both food and income insecurity. The effects of nitrogen and phosphorus fertilizer micro-dosing with inter-row rainwater harvesting practices for maize and pigeon-pea inter-cropping on yield and land use efciency are inadequately documented in sub humid tropics. A feld experiment on sandy loam soils in sub humid conditions using a splitsplit plot design was conducted. Plots used in situ rainwater harvesting practices of tied ridges, open ridges, and flat cultivation. Sub-plots were sole maize, sole pigeon-pea, and 1:1 maize-pigeon pea inter-cropping. The subsub plots were control, fertilizer (N and P) application at the micro-dose level, and recommended rates. Tied ridges signifcantly (p < 0.001) conserved more soil moisture than flat cultivation at 30 cm depth after ten days of rainfall. Ridges increased maize yield by 0.3 t ha−1 over flat cultivation. Fertilizer application signifcantly (p < 0.001) increased maize yield by 1.12 t ha−1 with micro-dosing and by 1.60 t ha−1 with recommended rates over the control. Combining tied ridges and fertilizer signifcantly (p < 0.040) increased maize yield by 132–156% compared to flat cultivation without fertilizer. Reflecting a land equivalent ratio, land use efciency was 67–122% higher in inter-cropping than sole crop. Tied ridges conserved more soil moisture than flat cultivation, enhancing fertilizer use efciency that improved crop yields and land equivalent ratio under intercropping. This strategy could increase food availability and income generation under smallholder farming systems in sub-humid tropic areas.