Browsing by Author "Mkonda, Msafiri Y."

Now showing 1 - 2 of 2

Accumulation of SOC in relatively undisturbed tropical mountain foothills under climate change scenarios: the case of Uluguru mountain, Tanzania
(Saudi Society for Geosciences and Springer Nature Switzerland AG, 2023-07-01) Mkonda, Msafiri Y.; Minja, Gileard S.; Ligate, Elly J.; Kaganga, Laison S.; Haule, Tiemo R.; Msemwa, Ubaya S.
Soil nutrients form an important part of agro-ecosystems in various landscapes, including mountainous areas. Most foothills in tropical mountains are heterogeneous in terms of the accumulation of soil nutrients due climatic location and ecological endowments. Since most mountain foothills have potential for the provision of environmental services, it is imperative to assess the salient soil nutrients including carbon in order to determine the amount. This study assessed the accumulation of soil organic carbon (SOC) in the relatively undisturbed foothills of Uluguru Mountains whose geology indicates that they were formed during cretaceous age (i.e. ≈50 million years ago). The study also determined the trends of rainfall and temperature because these elements of climate have important influence on carbon accumulation. In conducting this study, we sampled Kiroka Village (in Kiroka Ward) because it is found at the foothills of the Uluguru Mountain and most of its parts are relatively undisturbed. In this place, sixteen soil sampling points were established within one hectare and these points involved two soil depths (i.e. 0-20 cm and 20-40 cm) and two locations (i.e. lowland and upland). The Walkley–Black Method was used for SOC analysis while Mann–Kendall Test was employed for climate data analysis. The results exhibit that there have been significant variations in SOC accumulation under the two soil depths and locations. In the lowland areas, SOC was 1.1 and 0.43 MgC ha −1 for the depths 0–20 cm and 20–40, respectively. Besides, in upland areas, SOC was 0.38 and 0.31 MgC ha −1 for the depths 0–20 cm and 20–40, respectively. Most cereal crops require a considerable amount of SOC in the soil that ranges between 0.5 and 2 MgC ha −1 . Additionally, the mean annual rainfall and temperature patterns from 1980 to 2020 declined and intensified at R2 = 0.15 and 0.19, respectively. Therefore, these results inform environmental experts, climate practitioners and other relevant stakeholders to endorse suitable and sustainable environmental management methods in the mountainous areas.
The influence of soil organic carbon and climate variability on crop yields in Kongwa district, Tanzania
(Springer, 2022-01-07) Mkonda, Msafiri Y.; He, Xinhua
This study assessed the influence of soil organic carbon (SOC) accumulation and climate variability on crop yields in Kongwa District, central Tanzania. In doing so, climate data and soil samples were collected from Mnyakongo and Ugogoni villages through soil sampling, interviews and surveys. Walkley–Black method, Mann–Kendall test, and MS Excel were used to analyze SOC, climate, crop yields respectively. The results exhibited that the accumulation of SOC was significantly greater in soils under organic fertilization (1.15 and 0.80 MgC ha −1 at soil 0–20 cm and 20–30 cm depth) than under no- fertilization (0.35 and 0.30 MgC ha −1 at 0–20 cm and 20–30 cm) and decreased with increasing soil depths. Under these two soil treatments, the average yields for maize, sorghum and millet were almost 1.8 tn ha −1 under organic fertilization and 0.6 tn ha −1 under no-fertilization. Specifically, maize yields ranged from 1.5 to 2.2 tn ha −1 , while both sorghum and millet had 1.1–1.7 tn ha −1 . Therefore, yields were significantly higher under organic fertilizations than under no-fertilizations. Besides, the mean annual rainfall or temperature (1980‒2020) fluctuated at a decreasing (R 2 = 0.21) or an increasing trend (R 2 = 0.30). Comparatively, the yields for maize, sorghum or millet fluctuated at a decreasing trend at R 2 = 0.07, 0.05, or 0.85, respectively. Correspondingly, it was found that the temporal increase in rainfall and temperature had positive (R 2~0.5) and negative (R 2 ~0.3) correlations with crop yields, respectively. In contrast, the decline in rain’s intensity and frequency had negative impacts on crop yields. Thus, both SOC and climate correlated with crop yields.