Agroforestry (AF) is widely considered the most important tool to mitigate climate change-related issues by removing Carbon (C) Dioxide (CO2) from the atmosphere and storing C. Therefore, this study aims to broaden current knowledge on the impact of sustainable Agroforestry (AF) on the C sequestration rate and C stock in the surroundings of Cyamudongo isolated rain forest and Ruhande Arboretum. To understand this, the permanent sample plots (PSPs) were established mainly in the four designed transects of four km long originating on the Cyamudongo isolated rain forest boundary following the slope gradient ranging from 1286 to 2015 m asl. A total number of 73 PSPs were established in the Cyamudongo study area while 3 PSPs were established in the Ruhande AF plot. The Arc Map GIS 10.4 was used to design and map the sampling areas while GPS was used for the localization of the plots. Statistical significance was analyzed through R-software. The estimated quantity of sequestrated C for 2 years and 34 years of AF species was 13.11 t C ha -1 yr-1 (equivalent to 48 t CO2 ha -1 yr-1) and 6.85 t ha-1 yr-1 (equivalent to 25.1 t CO2 ha -1 yr-1) in Cyamudongo and Ruhande respectively. The estimated quantity of C stored by the Ruhande AF plot is 232.94 t ha-1. In Cyamudongo, the overall C stored by the AF systems was 823 t ha-1 by both young tree species established by the Cyamudongo Project (35.84 t ha-1) and C stored by existing AF species before the existence of the Project (787.12 t ha-1). In all study areas, the Grevillea robusta contributed more to overall stored C. The correlation coefficients between tree diameter and living biomass ranged from moderate to very strong due to differences in terms of age, stage of growth, and tree species.

Coffee is one of the most valuable cash crops in Rwanda. Coffee production in Rwanda stands high among three different export crops such as tea, pyrethrum, and was recently set as priority crop where more attention should be concentrated. This study estimates the impact of climate change and variation on coffee yield in Huye district, southern province of Rwanda. In this research both secondary and primary data were used and primary data were gathered from a random sample of 110 households in HUYE District. Coffee farmers were interviewed in August-September 2016 using structured questionnaires that were administered to household’s heads via person-interviews. Climate data (temperature and precipitation) were collected from the Rwanda Meteorological Station located in RUBONA Station. The results from climate change model has revealed that approximately 74% of change in the coffee production during the last 17 years was explained by climate factors jointly. The results indicate that coffee farms near Huye Mountain are highly vulnerable to precipitation variation like erosion during heavy rain in March through May and drought from June through August.

Conversion of land use from forest to agricultural uses modifies soil quality through physiochemical soil properties changes. This study was conducted in Rwanda’s central plateau agro-ecological zone to evaluate the effect of forest and agricultural land uses on soil quality. The study was conducted in 2020. Soil samples were collected at the top, middle and bottom positions of each of the two land uses. We analyzed soil bulk density, soil moisture content, soil pH, soil organic matter (SOM), total nitrogen (TN), available phosphorus (Av P), and CEC for each position of the land uses. Data were analyzed using ANOVA in GENSTAT version 13. The results revealed that soil properties were significantly affected by land use change. Analysis of variances (LSD<0.05) results showed, however, that treatments were not significantly different within the same land use. The results showed that treatments from top position of forest lands had the highest mean values for soil organic matter and total N parameters with the respective mean values of 6.58 %, and 0.37 %. Treatments from middle position of forest lands had the highest mean values for soil moisture content and Av P parameters respectively with 23.60 % and 29.56 ppm. But, soil bulk density was high on top position of agricultural land with a mean value of 1.49 g/cm3. Land users are advised to apply crop and soil management techniques which maintain soil quality and productivity on agricultural lands.