A study was carried out in Malawi to compare agronomic and socio-economic aspects of different water management practices for two advanced bean lines. Four irrigation technologies and one control were studied in Chingale Area Development Program in Zomba District in southern Malawi. The technologies encompassed motorized pumps (MP), treadle pumps (TP), water cans, gravityfed surface irrigation (GR) and a non-irrigated practice that used residual moisture. The study found that technologies that used \2 labour hours m -3 were appropriate for such small-scale irrigation systems. The aggregated bean production labour cost and labourday thresholds were $893 ha -1 and 2,978 LD ha -1 , respectively. An irrigation supply in the range of 7,000-10,000 m 3 ha -1 for the TP, MP and GR would be adequate. Assuming 20 irrigations season -1 , 400-600 m 3 irrigation -1 would be adequate, supplying 40-60 mm every 5-7 days. The study found that poor small-scale farmers in Malawi, particularly those using MPs, need fuel subsidies in order to offset operational costs. Basing on the findings in the study, we recommend further research on several bean lines in different agro-ecologies of Malawi using technologies that showed high yields, low labour efficiency and high water use productivity.

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Crop production in semi-arid sub-Saharan Africa (SSA) is limited by over-reliance on erratic and inadequate rainfall, which often results in yield reduction or total crop failure. The effects of frequent droughts and dry spells need to be circumvented by water conservation. Where rainwater is harvested, research recommendations are based on direct use of the water without relating it to catchment characteristics, climatic conditions and long term storage. A study aimed at predicting sizes of seasonal open surface reservoir based on rainfall and runoff rainwater was conducted from 2012 to 2013 at Ukwe Area, Malawi. The work premised on assessment of land and hydrological factors as they impinge on runoff water storage. Rainfall-runoff relative analysis showed runoff trend following the magnitude of rainfall. Findings showed that runoff water harvested, under the Ukwe area landscape conditions, is linearly related to seasonal rainfall amount with coefficient of correlation of greater than 0.75, demonstrating vitality of rain and timing of rain harvesting for reservoir sustenance. Runoff amount was almost four times that of infiltrated amount, highlighting the fact that drought prone areas can be flood prone as well. Results further demonstrate that weekly reservoir balance using crop, livestock and domestic consumption, and losses through evaporation and seepage, as dry season progresses are critical for reservoir sizing during dam construction or crop field sizing at the onset of dry season.

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