1,720,975 research outputs found
Response of Tef (Eragrostis Tef [Zucc.] Trotter) Yield to Nutrient Omission Under Irrigation at Sekota District, Waghimra Zone, Ethiopia
No full textA decrease in soil fertility has a significant impact on crop production and can impose limitations on overall yield. The experiment was conducted to determine the most yield-limiting nutrients for tef production in 2020 under irrigation. The experiment was laid out under a completely randomized block design with three replications. It comprises nine treatments, with one treatment of all nutrients nitrogen (N), phosphorus (P), potassium (K), sulfur (S), zinc (Zn), and boron (B) applied at the optimum level; other treatments were carried out by sequentially omitting each nutrient from all nutrient treatments. Nitrogen and phosphorus (NP) nutrients and no fertilizer were used as positive and negative controls. The sources of N, P, K, S, Zn, and B nutrients were urea, triple superphosphate, KCl, MgSO4, Zn-EDTA (granular), and borax (granular), respectively. Nitrogen was applied in two splits, half at planting and half at the vegetative stage and the remaining nutrients were applied once during planting. The results showed that the application different nutrient sources have significant effect (p <0.001) on the biomass yield (BY) and grain yield (GY)of tef. But the maximum aboveground BY and GY were obtained from the application of the NP nutrients, whereas the lowest GY was recorded from the control (no nutrients). The maximum yield reduction of biomass and grain from the applied nutrient was observed from the omission of N followed by phosphorus nutrients. The addition and omission of other nutrients did not show any yield difference on tef. Therefore, nitrogen and phosphorus nutrients were the most yield-limiting nutrients at Woleh irrigation scheme
Effects of nitrogen and phosphorus on potatoes production in Ethiopia: A review
No full textNitrogen and phosphorus are essential nutrients for all living organisms. They are critical determinants of plant growth and productivity. Hence, plants require these elements relatively in large amount. Despite the fact that, due to serious land degradation problem availability of those nutrients are depleted and the problem is common in the highland areas of Ethiopia. This paper is a review on application of inorganic fertilizer (nitrogen and phosphorus) for maximization of potato yield. Different researches conducted in the country shows that potato yield is declined due to an inadequate application of nutrient especially nitrogen and phosphorus fertilizers are the most limiting factors. Increasing application of nitrogen and phosphorus can maximize the yield and yield component of potato throughout the country. However, most farmers of the country have understood the importance of fertilizers, but due to different reasons they are not applying the fertilizers as recommendation. Lack of credit availability, high cost of fertilizer and lack of awareness on the use of organic fertilizer are the most limiting factors that affect the use of fertilizer. To feed the ever-increasing population of the country use of fertilizer is not an unsparing concern. Therefore, the application of fertilizer is one of the only means to maximize the production of potato for smallholder farmers to make their food security sustainable
Effects of nutrient omission on grain and biomass yield of irrigated wheat (triticum aestivum) in Sekota district, Amhara region, Ethiopia
No full textThe Ethiopian government has recently imported and distributed multi-nutrient fertilizers for farmers’ use without sufficient research findings. Hence, selecting the appropriate fertilizers based on the actual limiting plant nutrients is crucial for providing timely policy direction to import only fertilizers that could limit crop yield. A field study was carried out to identify the yield-limiting plant nutrients for wheat under irrigation at two farmer’s fields in the Woleh irrigation scheme of the Amhara region of Ethiopia in the 2022 irrigation season. A total of nine treatments, including control, NPSKZnB (all), NPSKZn (all-B), NPSKB (all-Zn), NPKZnB (all-S), NPSZnB (all-K), NKSZnB (all-P), PKSZnB (all-N), and RNP (all-KSZnB), were arranged in a randomized complete block design (RCRD) with three replications. The Kekeba wheat variety was used as a test crop. The collected grain and biomass yield data were analyzed using R software, following the procedure. The results showed that fertilizer application significantly affected wheat grain yield. The highest grain yield (4443.5 kg ha ^−1 ) was obtained from NPKZnB (All-S) treatment, though this was not statistically different from the yield achieved with the recommended NP treatment. While the lowest grain yield was obtained from the control and nitrogen omitted treatment. There was no significant difference between and among the treatments except control, all-N, and all-P. The grain yield was reduced by 3181.6 kg ha ^−1 when N was omitted and 1817.8 kg ha ^−1 when P was omitted over all-S (NPKZnB). This showed that nitrogen and phosphorous are yield-limiting plant nutrients for wheat under irrigation in the study area. Therefore, the government should give emphasis to nitrogen- and phosphorous-containing fertilizers to increase wheat yield
Land capability classification and suitability assessment for selected crops in Gateno watershed, Ethiopia
No full textThe aim of the study was to evaluate the capability and suitability of the land for rain-fed major crop production. The study was conducted in Woleh Kebele of Sekota Woreda Wag-Himira administration zone in Ethiopia. In this study area, four homogeneous land units were identified based on topography. Soil survey was conducted on each land unit to observe the physical and chemical properties of the soil. The soil property analysis results indicate that the area is highly susceptible to erosion and low fertility that limit the land capability for various cultivated lands. The land capability assessment was undertaken based on USDA criteria. The results showed that three land unit maps were rated as capable for rain-fed crop production, whereas the fourth land unit was not capable due to permanent limitations associated with slope and soil depth. The land suitability assessment for rain-fed major crops was performed by using the maximum limitation method. The results showed that three land unit maps were marginally suitable for wheat and faba bean and not suitable for barley, due to poor soil fertility, slope, and high erosion. The potential land suitability results showed that 7.05% of land is highly suitable for barley and wheat but moderately suitable for faba bean, 25.04% moderately suitable for barley and wheat but marginally suitable for faba bean, 58.65% marginally suitable for barley and wheat but not suitable for faba bean, and 9.3% not suitable. The land suitability of the area can be enhanced by implementing appropriate interventions such as soil and water conservation, improving soil fertility, and agronomic practices
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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