Browsing by Author "Mzirai, O.B."

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    Performance of maize under micro-catchment rainwater. harvesting in western Pare lowlands and Morogoro, Tanzania
    (1999) Hatibu, N.; Gowing, l.W.; Mzirai, O.B.; Mahoo, H.P.
    Micro-catchment Rainwater Harv.esting. (RWH) has been defined as a method of collecting run-off from a Catchment Area (CA) over short distances not exceeding 100 m and supplying it to an adjacent Cultivated Basin (CB). It is a system that is designed to concentrate rainwater so as to utilize it more effe"ctively in areas- where. the seasonal. rainfall amounts are frequently lower than crop water requirements. The Catchment to Basin Area Ratio (CBAR) is an important parameter in the design of micro-catchment systems. It usually varies between 1:1 and 10:1. However, methodsfor deciding the optimumle·ve! of CBAR for differef!t farming systems are not available. The purpose of the experiments reported here was to evaluate the CBARfor maize production in semiarid areas of Tanzania. The experiments were run between 1992 and 1995. in semi-arid areas of Morogoro and Mwanga Districts of Tanzania, to assess the peiformance of maize grown in microcatchment systems with CBAR varying from 0:1 to 4:1. Maize var. TMVI was grown in Mwanga District while maize-var. Staha was used as a test crop in Morogoro District. Grain was harvested in five out of six experimental seasons in Mwanga (Masika 1993, 1994 and 1995 and Vuli 199411995 and 199511996). In Morogoro, grain harvest was obtained only in two seasons (Masika 1993 and 1994) out offour. The results showed that micro-catchment RWH farming is feasible during Vuli. The yield benefits due to RWH were found to be 120 - 152· % and significant at P = 0.05. The benefits during Masika were found to be very low at only 12 - 17 % and not significant at P = 0.05.
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    Review of rainwater harvesting techniques and evidence for their use in semi-arid Tanzania
    (1999) Gowing, J.W.; Mahoo, H.F.; Mzirai, O.B.; Hatibu, N.
    Raillwater h.{pvesting (RWH) ,shuuld"be 'regarded as a continuum of techniques thill' link in-situ soil-wate!: conservation at on~'exi;-'ellle to co'nventiona!irrigation {it the ·other. bHitu KWH, comprises i~ group of techniques for preventing runoff and promoting infiltration: Mic/'()-catc~mellt RWH comprises'a group'oftechniques/or collecting overlandfZow;(sheetor rill) from a catchment area and delivering it to a cropped.area in order to supplement the inadequate direc·t':air!faZ{ The transfer nomllllly occurs ·over a reJativelyshOit distance entirely withirt the land-holding of an individual farmer and the system is therefore sometimes known as 'an "illtemai cauhment" .. Macro-catchment RWH comprises a group' of techniques in which natural runoff is collected Fum a relatively large area .and. tr(1nsferred over.a longer distance. Examples of each pf these categories of RWH exist' ill p'a,t's 0/ Ta,';iania, but their potential is }eirgely neglected, by research and extension"seivices alzd they are illlder-exploited. The pUipose of this paper was to 'assess the extent to which thediflerent rainwater harvesting systeniS, are used in Tanzania. The findings show that there is a widespread practice of rainwater harvesting in Tanzania. Rainwater hmvestillg with storage of wate!' for livestock has received govemment SUppOit in the past . . However, rruzny storage reselvoir~ have been destroyed by siltation. On the other hand rainwater hmvesting for crop production has llOt received an adequate SUppOit from research and extension services. Therefore, although farmers are practiciizg rainwaterhmvesting, they are faced with sh01tage of appropriate technolo giesand know