Assessment of botanical composition, biomass yield, nutritional quality and methane production of forages in selected grasslands, southern highlands of Ethiopia

A study was conducted to assess botanical composition, biomass yield, nutritive value and methane production of forages in the grasslands of Kofele district in West Arsi Zone of Oromia National Regional State, southern Ethiopia. Three patches of the grassland including protected grassland, private grazing land used by smallholder farmers and ranch were selected for the study to represent three different grazing land management practices. Quadrats of 0.5 m × 0.5 m were used to determine biomass yield and collect samples of herbaceous forages from each site (12 quadrats from each site). For woody species four 10 m × 10 m plots were established along transect of 200 m with 20 m distance between plots to identify available species (in the ranch only). A total of 20 herbaceous species were identified, out of which 45% were grasses, 15% legumes, 10% sedges and 30% forbs. Out of 17 browse species identified in the ranch, 47.1% were trees while 52.9% were shrubs. The total biomass production from protected grassland (4.34 t/ha) was higher (P<0.05) than that of private grazing land (3.66 t/ha) and ranch (3.76 t/ha). Biomass production of sedge and forbs were the highest (P<0.05) in ranch. The ranges of chemical constituents for grasses were 8.44–10.74%, 52.8–72%, 27.7–37.4%, 3.1–5.6%, 58.2–76% for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) and in vitro dry matter digestibility (IVDMD), respectively. The CP and IVDMD for legumes varied from 15.64–20.33% and 80.1–85–1%, respectively. For browses the ranges of CP and IVDMD were 15.41–27.19% and 57.4–81.9%, respectively.. Among grass species, Eragrostis botryodes generated less methane. In general, legumes (5.5–6.5 mL/200 mg) and sedge (6 mL/200 mg) produced less amount of methane compared with grasses (7–10.5 mL/200 mg). Browses (9.5–13.5 mL/200 mg) produced more methane compared with herbaceous species (5.5–10.5 mL/200 mg). In conclusion protecting grassland and using cut and carry feeding system promoted more herbage production. The CP content of grass is generally good but supplementation with legumes and browses are required in practical feeding. The use of legumes with grasses and other browse species is recommended as a feeding strategy to reduce methane production However; further investigations on animal response trials are suggested to see the potential of these feed resources

Assessment of botanical composition, biomass yield, nutritional quality and methane production of forages in selected grasslands, southern highlands of Ethiopia

A study was conducted to assess botanical composition, biomass yield, nutritive value and methane production of forages in the grasslands of Kofele district in West Arsi Zone of Oromia National Regional State, southern Ethiopia. Three patches of the grassland including protected grassland, private grazing land used by smallholder farmers and ranch were selected for the study to represent three different grazing land management practices. Quadrats of 0.5 m × 0.5 m were used to determine biomass yield and collect samples of herbaceous forages from each site (12 quadrats from each site). For woody species four 10 m × 10 m plots were established along transect of 200 m with 20 m distance between plots to identify available species (in the ranch only). A total of 20 herbaceous species were identified, out of which 45% were grasses, 15% legumes, 10% sedges and 30% forbs. Out of 17 browse species identified in the ranch, 47.1% were trees while 52.9% were shrubs. The total biomass production from protected grassland (4.34 t/ha) was higher (P<0.05) than that of private grazing land (3.66 t/ha) and ranch (3.76 t/ha). Biomass production of sedge and forbs were the highest (P<0.05) in ranch. The ranges of chemical constituents for grasses were 8.44–10.74%, 52.8–72%, 27.7–37.4%, 3.1–5.6%, 58.2–76% for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL) and in vitro dry matter digestibility (IVDMD), respectively. The CP and IVDMD for legumes varied from 15.64–20.33% and 80.1–85–1%, respectively. For browses the ranges of CP and IVDMD were 15.41–27.19% and 57.4–81.9%, respectively.. Among grass species, Eragrostis botryodes generated less methane. In general, legumes (5.5–6.5 mL/200 mg) and sedge (6 mL/200 mg) produced less amount of methane compared with grasses (7–10.5 mL/200 mg). Browses (9.5–13.5 mL/200 mg) produced more methane compared with herbaceous species (5.5–10.5 mL/200 mg). In conclusion protecting grassland and using cut and carry feeding system promoted more herbage production. The CP content of grass is generally good but supplementation with legumes and browses are required in practical feeding. The use of legumes with grasses and other browse species is recommended as a feeding strategy to reduce methane production However; further investigations on animal response trials are suggested to see the potential of these feed resources.The International Atomic Energy Agencyhttp://www.elsevier.com/locate/sciafhj2022Animal and Wildlife Science

Estimation of Groundwater Recharge in a Volcanic Aquifer System Using Soil Moisture Balance and Baseflow Separation Methods: The Case of Gilgel Gibe Catchment, Ethiopia

Understanding the recharge–discharge system of a catchment is key to the efficient use and effective management of groundwater resources. The present study focused on the estimation of groundwater recharge using Soil Moisture Balance (SMB) and Baseflow Separation (BFS) methods in the Gilgel Gibe catchment where water demand for irrigation, domestic, and industrial purposes is dramatically increasing. The demand for groundwater and the existing ambitious plans to respond to this demand will put a strain on the groundwater resource in the catchment unless prompt intervention is undertaken to ensure its sustainability. Ground-based hydrometeorological 36-years data (1985 to 2020) from 17 stations and satellite products from CHIRPS and NASA/POWER were used for the SMB method. Six BFS methods were applied through the Web-based Hydrograph Analysis Tool (WHAT), SepHydro, BFLOW, and Automated Computer Programming (PART) to sub-catchments and the main catchment to estimate the groundwater recharge. The streamflow data (discharge) obtained from the Ministry of Water and Energy were the main input data for the BFS methods. The average annual recharge of groundwater was estimated to be 313 mm using SMB for the years 1985 to 2020 and 314 mm using BFS for the years 1986 to 2003. The results from the SMB method revealed geographical heterogeneity in annual groundwater recharge, varying from 209 to 442 mm. Significant spatial variation is also observed in the estimated annual groundwater recharge using the BFS methods, which varies from 181 to 411 mm for sub-catchments. Hydrogeological conditions of the catchment were observed, and the yielding capacity of existing wells was assessed to evaluate the validity of the results. The recharge values estimated using SMB and BFS methods are comparable and hydrologically reasonable. The findings remarkably provide insightful information for decision-makers to develop effective groundwater management strategies and to prioritize the sub-catchments for immediate intervention to ensure the sustainability of groundwater