Various ecological and environmental indicators including climate change, soil fertility, water availability and proper agronomic practices that form optimal agricultural systems are needed to be integrated for increasing agricultural productivity in the Tanzanian semi-arid agro-ecological zone. Among these indicators, climate change and soil fertility are the major limiting factors to affect crop yields in this semi-arid agro-ecological zone. To improve crop productivity, this study assessed the accumulation of soil organic carbon (SOC), the trends of climate variability and crop production, and the rate of adopting conservation agriculture (CA) in the Kongwa District, a semi-arid zone in central Tanzania. In doing so, climate data and soil samples were collected from two representative villages of Mnyakongo and Ugogoni. These the villages are located at (6°12′8.47″S, 30°23′25.25″E and 6°15′6.59″S, 30°27′8.78″E), respectively, with 900– 910 m above sea level and are located in one of the most sensitive zones to climate stress. The annual precipitation varies with elevation and ranges from 400 mm at 900 m a.s.l. to 800 mm at 1000 mm a.s.l., and the dominant soils are fluvisols and vertisols. Field experiment was conducted between June and September, 2016, whereas, soil samples were collected from pits in July, 2016.