Major Ions in Atmospheric Deposition in Lake Kivu Basin

This study investigated the major ion composition and sources in wet and dry deposition samples collected over 15 months (December 2017 to February 2019) at four stations representing four different land use/cover types on the western side of Lake Kivu basin in D.R. Congo. The samples were collected every 13 days for dry deposition and two to three times per month for wet deposition. Samples were analyzed for major ionic components (Cl-, NO-3, SO2-4, Na+, K+, NH+4, Ca2+, CO2-3, HCO-3 and Mg2+). Electrical conductivity and pH were analyzed immediately in the field while major ion measurements were in the laboratory. Results showed the pH of both the dry and the wet depositions were higher than what would have been expected based on equilibration with atmospheric CO2 (pH > 5.6) at all four sites, with conductivity less than 50 μS/cm. The neutralization process in dry and wet atmospheric deposition is due to Ca2+, NH+4, HCO-3 and CO2-3. The anion: cation ratio in dry deposition was close to 1 for Iko and Bukavu, and it was greater than 1.0 (1.1 - 1.2) for Lwiro and Goma in wet deposition. The dominant anions in wet deposition were SO2-4 and NO-3, found around the rural area near cement factory and the urban area near active volcanoes, respectively. The most abundant cation was Na+ followed by K+. The enrichment factors and correlation analysis suggest that the main sources of Ca2+, Na+ and Mg2+ were disintegration of soil processes, aeolian suspension of soil and volcanic ash, biomass burning and the cement/lime factory around the Lake Kivu basin.

Spatio-Temporal Variation of Atmospheric Nutrient Deposition in Different Land Uses/Covers around Lake Kivu

Atmospheric deposition of nutrients, particularly nitrogen and phosphorus has the capacity to significantly affect the productivity and biogeochemistry of aquatic ecosystems. The objective of this study was to assess the impact of land use/cover types on the atmospheric deposition of nutrients around Lake Kivu. Dry and wet atmospheric deposition samples were collected from four different land use/cover types (forest, wetland, agricultural and urbanized area) at four stations (Goma, Lwiro, Bukavu and Iko) around the Lake Kivu basin. The highest annual loading of dry total phosphorus (TP) was recorded at a station located in an urban area at Goma (4.4 ± 3.9 μmol/m2/yr) and the highest dry deposition of total nitrogen (TN) was recorded at Iko (84.5 ± 41.2 μmol/m2/yr). High wet TP and TN were at Bukavu (0.7 ± 1.1 μmol/m2/yr) and Iko (21.7 ± 34.7 μmol/m2/yr) respectively. High dry TP loads were recorded in the forest area of Goma and the highest dry TN at Lwiro. High wet TP loads were record in agriculture at Goma and high values of wet TN in agriculture at Iko. Phosphorus and nitrogen deposition rates around Lake Kivu were similar to those reported for other African lakes. The highest rate of TP was recorded mainly in the forest area for dry deposition while high TN was recorded in all types of land use/cover in the basin. This study found out that forest traps high concentration of nutrient than other land uses/covers.

Production Systems, Genetic Diversity and Genes Associated with Prolificacy and Milk Production in Indigenous Goats of Sub-Saharan Africa: A Review

Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.

Effect of Applying Low Rates of Agricultural Lime and Chicken Manure on Selected Soil Properties on Ferralsols of Lake Victoria Agro-Ecological Zone, Uganda

Ferralsols form a dominant type of soil on which most crops are grown in the Lake Victoria agro-ecological zone. Soil acidity has been recognized among the most important agricultural problems in such soils, which adversely affect crop production and productivity. A study was conducted with the objective of determining the effect of applying low rates of lime and chicken manure on selected soil chemical properties. Using a Split Plot Factorial Randomized Complete Block Design, agricultural lime (0.0, 0.5, 1.0, 1.5 & 2.0 t·ha-1) as the main plot and chicken manure (0.0, 1.0, 2.0 & 3.0 t·ha-1) as sub-plot were applied, replicated three times. The test crop was common bean var. NABE 15. The experiment was conducted for three rainy seasons, two seasons on-station and one season on-farm on Ferralsol soil in the Lake Victoria crescent of central Uganda. The results showed that applying low rates of lime with chicken manure significantly (p ·ha-1 lime was applied with the four chicken manure rates in Mukono. From the study, we recommend the application of small quantities of lime at 1.0 t·ha-1 with either 2.0 or 3.0 t·ha-1 chicken manure.