Evaluation of farming systems effects on spatial and temporal variability of soil moisture, organic carbon and bulk density in rain-fed lowlands of Laikipia County, Kenya

Abstract

A study to determine the effects of farming systems on spatial and temporal variability of soil bulk density, soil organic carbon and soil moisture was carried out in lowland areas of Laikipia during 2019 and 2020 cropping seasons. Soil sampling was carried out from 3m x 3m plots, demarcated in 30 selected farms practicing conservation agriculture (CA), conventional farming(CF) and from a bordering fallow reference land (RL). Ten soil samples/cores from each plot were collected at 20cm depth, using metallic soil augers of 5cm diameter and core ring samplers of 5cm diameter and 10cm height, air dried taken for lab analysis to determine the soil attributes. Findings indicated that the percentage soil moisture in farms adopting conventional farming was significantly lower than that adopting conservation agriculture. The mean soil bulk density under convention farming was 1.35 ± 0.06 g/cm³, while farms under conservation agriculture had a mean bulk density of 1.78 ± 0.04 g/cm³ and 1.13 ± 0.04 g/cm.³ in uncultivated reference land. Overall, the highest levels of total soil organic carbon were 61.9gkg^-1 under CA and 35.3gkg^-1 under CF. These findings could show that the adoption of CA can substantially affect the selected soil physical properties and potentially enhance soil quality and productivity in the study area.