灌溉排水系统工程

The study analyses the efficacy of rainfed and irrigated smallholder farms in Tchien district of Liberia. A total of 120 respondents were randomly selected from 5 rural communities around the major rice-producing areas of Tchien District: Gaye town, New Zleh, Old Zleh, Turglor, and Ziah. A total of 58 irrigation farmers and 58rainfed farmers, comprising of 61 male and 57 female rice farmers were interviewed.The study is empirical, taken under different variables to decide the appropriate agricultural system, and the variables to be employed in determining a successful production system. The study applies both the stochastic frontier analysis (SFA) to determine the efficient utilization of production inputs, and the logit model was used to measure the adoption of an irrigation system. Findings suggest that there is a serious disparity in efficiency between rainfed and irrigated farms, implying that irrigated farms are twice as efficient as rainfed farmers; most of the farmers are likely to adopt irrigation systems. Concerned institutions should work to improve access to capital, encourage irrigation farming, and work to effectively integrate experience farmers with young farmers.

Soil moisture stress condition is the most critical factor affecting crop yield and water productivity. Under changing climate and increasing human population the evaluation of effect of soil moisture stress on crop production is critical issue for the increasing water scarcity. An experiment was conducted for three consecutive seasons to investigate the effect of water stress imposed at different growth stages on bulb yield and water productivity of onion (Allium cepa L.). Sixteen treatments were used depriving irrigation at different combinations of the four growth stages: at each growth stages, at two growth stages, at three growth stages, irrigated at establishment only and full irrigation (control).

A field experiment was conducted during the dry season of 2017/2018 at the Sibu Sire district East Wollega zone of Oromia Regional State to evaluate the impact of furrow dimensions on yield and water productivity of maize. Climatic, plant and soil factors were used for the calculation of monthly crop water and irrigation requirements and results compared with actual performance of the irrigation system. The experiment was laid out in a randomized complete block design with three treatments replicated four times. The experimental treatments including Farmer practice or Furrow with top width of 21cm, bottom width of oi; 13cm and depth of 10cm without determined flow rate (T1), Furrow with top width of 25cm, bottom width of 14cm and depth of 15cm with determined flow rate (T2) and Furrow with top width of 18cm, bottom width of 8cm and depth of 12cm with determined flow rate (T3) having a plot size of 6m x 8m with spacing of 0.5m and 1m between plots and replications respectively.

In semi-arid areas where agricultural development is highly constrained by water scarcity and its mismanagement, the need to use the available water resources efficiently is important. The aim of the study was to evaluate the effect of different irrigation levels on seed yield, yield components and water productivity of onion (Allium cepa L.). The experiment was carried out on two farmer’s field on Midhagdu small scale irrigation scheme at Oda Bultum district, West Hararghe Zone during 2018/19 irrigation season. The experiment was laid out in a randomized complete block design with three replications of five irrigation levels (i.e.100, 90, 80, 70 and 60%) in combination of four growth stages (vegetative, bolting, flowering and seed formation) with non-deficit at all growth stages used as control. The combined result of deficit furrow irrigation techniques indicated that there were significance difference (p<0.05) between onion seed yield and water productivity but no significance difference (p>0.05) were observed on growth parameters. The highest mean seed yield and net return were gained from 20% deficit at vegetative stage with higher benefit-cost ratio indicating better onion seed yield is found with mild water stress and reduced with increase in water stress. Thus, the findings summarized that using deficit irrigation of 20% were economically profitable and saves water than full irrigation at all growth stages.

This study reviewed to identify factor affecting irrigation agriculture in Ethiopia. Although Ethiopia has abundant land for irrigation, only a fraction of its potential land is being utilized due to different factors like environmental, social and climate-related, economic and political, the land issue and rural land laws. Related with irrigation agriculture and rural land issue the government of Ethiopia has no visible document. So, as a recommendation since ,the land policy of Ethiopia was, the result of a centralized, top-down approach rather than being developed through consultations with all concerned parties and it impedes the development of irrigation agriculture in the country, it needs to be resolved quickly in order to develop irrigation agriculture based on the irrigation potential of the country.