RESUMO
Ethiopia has a huge potential to increase the production and productivity of potato (Solanum tuberosum L.) mainly in north-western regions where current potato yields are less than 10 t ha-1. Soil fertility and disease are the major yield-limiting factors of potato in this part of the country. Three-year's on-farm research was conducted to get the optimum economic levels of nitrogen (N) and phosphorus (P) nutrients for the major potato-growing areas of north-western Ethiopia. A factorial experiment with four levels of N (46, 92, 138, and 194 kg ha-1), three levels of P2O5 (46, 69, and 92 kg ha-1), and one pilot treatment with no NP nutrient inputs was used. A randomised complete block design with three replications was used. The findings of the research showed that more than 40 t ha-1of potato could be attained (about four times the current productivity) in the study areas through NP nutrient management. The yield was increased significantly with an increased rate of N at all sites (p < 0.01). The yield difference was nonsignificant (p > 0.05) between P levels for most of the sites and years. The financial analysis of the findings for Yilmana Densa district indicated that applying 138 N and 46 P2O5 kg ha-1, together, gave a marginal return of (Birr/Birr) 70.9, whereas 138 N and 69 P2O5 kg ha-1 resulted in 10.7. For the South Gondar, 138 N and 46 P2O5 kg ha-1 gave a marginal return of 24.3 (Birr/Birr). Therefore, based on the farm gate price of potato and the cost of fertilizer, 138 N, combined with 69 P2O5 kg ha-1, is recommended for the Yilmana Densa. For the South Gondar, 138 N, combined with 46 P2O5 kg ha-1, is recommended.
RESUMO
Soil fertility management through inorganic fertilizer application in areas with moisture shortage needs due care. The fertilizer application fashion should vary from areas with ample moisture so that the plants can easily access and efficiently use it. Therefore, field experiment was conducted in 2014 and 2015 during the main cropping season under rain-fed condition to evaluate the effect of micro-dose application of N and P fertilizers on sorghum yield at Aybra and Shumshiha sites of Wag-Lasta areas in Amhara Region, Ethiopia where moisture shortage is acute. The treatments were comprised of a factorial combination of three levels of NP i.e. 1), 25% of the recommended NP = 10.25 kg N + 11.5 kg P2O5 ha-1, 2), 50% of the recommended NP = 20.5 kg N + 23 kg P2O5 ha-1 and 3), 75% of the recommended NP = 30.75 kg N + 34.75 kg P2O5 ha-1 and three N application times plus control (without fertilizer) and recommended NP (41 kg N ha-1 and 46 kg P2O5 ha-1). The experiment was laid down in a randomized complete block design with three replications. The fertilizers were applied to the spot where the seed was planted except for the recommended NP which was drilled to the planting rows right before planting. Phosphorus was applied at planting while nitrogen was applied in split as per the treatment setup. All soil and agronomic data were collected and analyzed following the standard procedures. The analysis of variance revealed that application of 30.75 kg N ha-1 and 34.5 kg P2O5 ha-1 (N applied 1/3 at sowing, 1/3 at emergence and 1/3 at 45 days after emergence) increased the grain yield by 122% over the control and 28.4% over the recommended NP and saves 25% of the recommended fertilizer at Aybra. While at Shumshiha-Lasta Lalibela, application of 20.5 kg N ha-1 and 23 kg P2O5 ha-1 (N applied 1/3 at sowing, 1/3 at emergence and 1/3 at 45 days after emergence) increased the grain yield by 174% over the control and 15% over the recommended NP and saves 50% of the recommended fertilizer. Therefore, micro-dosing application of 30.75 kg N ha-1 and 34.5 kg P2O5 ha-1 for Aybra-Sekota and of 20.5 kg N ha-1 and 23 kg P2O5 ha-1 for Shumshiha-Lasta Lalibela (N applied in three splits) are recommended for sorghum production.
RESUMO
Establishing exclosures has become common in Ethiopia, especially in the central and northern highlands, where they serve as a response to persistent forest degradation, affecting forest resources and ecosystem services. We investigated changes in vegetation composition, aboveground biomass and soil properties after establishing an exclosure on degraded communal grazing land in Aba-Gerima watershed, North-Western Ethiopia. We selected 4-yr-old exclosure and paired the selected exclosure with an adjacent communal grazing land. In the exclosure, we recorded 46 plant species representing 32 families, whereas we recorded 18 plant species representing 13 families in the adjacent communal grazing lands. Most of the identified woody species are economically important. We observed significant differences between the exclosure and adjacent grazing land in woody species richness, diversity and evenness. Exclosure displayed higher woody species density, basal area and aboveground woody biomass compared to the adjacent grazing land. Landscape position influenced vegetation composition, richness and diversity in the exclosure and adjacent grazing land. Significant differences between the exclosure and adjacent grazing land in soil properties were detected. The influence of landscape positions on soil properties was not consistent. At foot slope position, in the 0- to 15-cm and 15- to 30-cm depths, soil organic carbon and nitrogen content detected in exclosure were significantly higher when compared to the values observed in the adjacent grazing land. However, differences at mid and upper slope positions were not significant. The results support that the establishment of exclosures on degraded lands could support the restoration of degraded native vegetation and soil properties, which consequently enhance the ecosystem services that can be obtained from degraded lands.
