Response of potato (Solanum tuberosum L.) to nitrogen and phosphorus fertilizers at Sekota and Lasta districts of Eastern Amhara, Ethiopia

Background Production and productivity of potato in Ethiopia is far below the world average because of soil fertility problem, pest, disease, and agronomic factors. Nutrient depletion because of soil erosion is a serious problem in Ethiopian highlands. Annually, 122 kg ha−1 nitrogen, 13 kg ha−1 phosphorous and 82 kg ha−1 potasium were estimated to deplete from Ethiopia (Haileslassie et al. 2005). From the essential nutrients especially, nitrogen and phosphorus are the most important influential elements for production of potato but they are deficient in most Ethiopian soils and thus an application of these nutrients could increase significantly the crop yields. Therefore, the experiment was conducted at Sekota and Lasta Lalibela districts (Woleh and Kechin Abeba irrigation command areas) of eastern Amhara, Ethiopia to investigate the effects of nitrogen and phosphorus fertilizers for yield and yield component of potato under irrigation condition. Methods Four rates of nitrogen (0, 46, 92, and 138 kg N kg ha−1) and phosphorus (0, 23, 46, and 69 Kg P2O5 kg ha−1) were combined with factorial arrangement and laid out in randomized complete block design with three replications. Results The result of the study revealed that nitrogen and phosphorus had a significant effect on plant height, marketable, and total yield of potato at Kechin Abeba. But phosphorus did not show a significant effect on plant height and unmarketable yield at Sekota district of Woleh irrigation command area. The highest yield 45.55 t ha−1 was obtained from combined application of 138 N and 23 P2O5 in Lalibela 17.12 and 16.99 t ha−1 were found from application of 138 N with 46 P2O5 kg ha−1 and 138 N with 23 P2O5 kg ha−1 from Sekota district of Woleh irrigation command area respectively. Conclusions The application of 138 kg ha−1 N with 23 kg ha−1 P2O5 is the appropriate rates for optimum productivity of potato at Lalibela (Kechin Abeba) and Sekota (Woleh) irrigation command areas and the same agro-ecology.

Farming carps in leased ponds by groups in Chandpur, Bangladesh.

This case study was prepared as part of an Asian Development Bank (ADB) Special Evaluation Study (SES) on Small-Scale Freshwater Rural Aquaculture for Poverty Reduction. The SES used primary and secondary data and published information to document the human, social, natural, physical and financial capital available to poor people involved in the production and consumption of freshwater farmed fish and to identify channels through which the poor are affected, such as through access to livelihood assets, markets and prices, access to services and facilities, and key institutions and processes. The case study is based on a part of the small-scale fisheries development component of the ADB-financed Command Area Development Project (CADP). The project developed on-farm field irrigation channels, improved the existing water distribution and drainage systems, and provided minor flood protection in the respective command areas of Pabna Irrigation System (PIS) located in Pabna District and Meghna-Dhonagoda Irrigation System (MDIS) located in Chandpur District. This case study focuses on small-scale freshwater aquaculture development in Matlab Upazila of the MDIS command area. An Upazila is an administrative government unit consisting of unions, each of which consists of villages. Aquaculture was developed within the irrigation command areas by providing extension services, organizational and management development support, and credit inputs primarily in small ponds for the poor.

ENSO modulated groundwater variations in a river basin of Central India

Several previous studies have examined the traceable regional impacts of El Niño Southern Oscillation (ENSO) on groundwater level (GWL) but it remains a question whether the ENSO impacts on groundwater can be established in smaller basins using statistical techniques. The present study attempts to record the ENSO impacts on the groundwater availability in Venna basin, Maharashtra by proposing a combination of statistical and spatial analysis. Utilizing the GWL, the study estimates the spatial variability of GWL, groundwater anomalies, groundwater recharge and discharge using geographic information system (GIS) and quantitative variations in groundwater using statistical techniques. The study also highlights the applicability of the Kolmogorov–Smirnov test in hydrometeorological studies. Analyses reveal the association of deeper GWLs and higher discharge with the El Niño, as opposed to shallower GWLs and higher recharge with La Niña. The two-sample Kolmogorov–Smirnov test confirms the discrepancy in the cumulative distribution of GWL between different ENSO phases. Mann–Kendall, Sen slope and Mann–Whitney tests ascertain the variation of GWL and recharge as well as ENSO impacts in the command area (area irrigated by reservoir using the canal networks) and non-command areas. A significant difference in recharge between El Niño and La Niña is observed in the command as well as in the non-command areas.