Haramaya University

Digital libraries offer technology based information resources and services to enable learners to access relevant knowledge anywhere anytime. As such, digital libraries are inseparable from the learning process because they made e-learning possible. The aim of this study is to explore the role of digital library in higher education from a student's perspective and To identify major digital libraries which offer educational information resources and services as part of their Web 2

Rice agronomy plays a great role in increasing and sustaining rice production and productivity. Due mainly to its relatively recent history of cultivation in Ethiopia, the scientific information available with regards to the response of rice to N and P sources of fertilizers for its production is very limited. An experiment was conducted in 2014 and 2015 in Tigray, Ethiopia, with the objectives of determining the economically optimum rates of N & P sources of fertilizer on yield of rice. Five levels of N (0, 23, 46, 69 and 138 kg N/ha) and four levels of P (0, 23, 46 and 69 kg P 2 O 5 /ha) Factorial experiment was laid out in a randomized complete block design with three replications. The interaction effects of N and P were significant (P ≤ 0.05) for grain yield, biomass yield, plant height and days to heading but not for days to maturity, harvest index and thousand seed weight. From the view point of the physical (agronomic) yield, the combined results of the experiment revealed that the combination of 138 kg N/ha and 46 kg P 2 O 5 /ha recorded maximum grain yield of 5723 kg/ha and the control (i.e. no N and no P) gave the lowest grain yield (1601 kg/ha). Unlike that of the agronomic yield, the economic analysis of the combined result of the experiment with two years and two locations revealed that the profitable mean net return of 22208.63 Birr/ha was obtained for the plot that received 69 kg N/ha and 23 kg P 2 O 5 /ha which is 11185.12 Birr more than the net returns obtained from the control (with no urea plus no DAP) which is Birr 11023.51 birr. Therefore, from the economically profitable fertilizer rate use point of view, rice farmers in Tselemti district and similar areas should use the most economically feasible fertilizer rate with highest value of marginal rate of return i.e. 69 kg N/ha with 23 kg P 2 O 5 /ha.

This study investigated the combined effects of deficit irrigation under drip irrigation system and mulches on yield and water-use efficiency on tomato production at Miawa Farmer Training center, south Wollo, and Kallu worda during 2016 irrigation season. A factorial combination of three levels of water (namely 70%, 80% and 90% ETc) combined with three mulch treatments (namely, without mulch (WM), sugarcane mulch (SM) and bulrush mulch (BM)) with three replications. The yield and yield-contributing all parameter in the mulched treatments for all levels of irrigation there is significantly difference compared to those in the un-mulched treatments. The yield of tomato increased with the increasing amount of irrigation water in un-mulched treatment. The trend was reversed when drip irrigation was coupled with mulches. The highest yield for each mulch (44.04 t/ha for sugarcane and 30.19 t/ha for bulrush) was obtained when 80% and 90% of water requirement was applied respectively. With 9...