Infiltration and hydraulic conductivity ( K) play a key role in streamflow generation and groundwater recharge. The impact of agriculture on soil infiltration and K has been widely investigated. While many studies show decreases in infiltration and K, others show an increase or no change in both parameters. These variations highlight the importance of conducting local scale investigations. We investigated the impact of agricultural development and land cover changes on infiltration and K. Unsaturated hydraulic conductivity (K unsat) was measured at the soil surface during both dry and wet seasons and saturated hydraulic conductivity (K sat) was measured at 25, 45, and 65 cm below the surface. Our results show that there were no significant differences in K unsat between perennial crop cover and natural forests; however, agroforests did have significantly higher K unsat than natural forests, which was attributed to higher soil moisture. There were no significant differences in K sat among the perennial crops, agroforests and natural forests at the 45 and 65 cm depths; however, at 25 cm natural forests had significantly higher K sat, which was attributed to the higher soil organic matter and lower bulk density in natural forest. The study showed that the impacts of agriculture and land cover change on K sat does not extend to deeper soil layers. We used two years of rainfall intensity data, observed K unsat and K sat , and HYDRUS-1D modelling to infer any changes to runoff. We show that footpaths and perennial crop cover may generate more surface runoff than natural forests. This study adds to the literature on agricultural impacts on infiltration and K. More importantly it shows that differences in crop type, management practices and topographic location all play an important role on infiltration and K, showing the need for local field based studies.

Our understanding of the hydrological processes in cocoa agroforests is extremely limited. Most work has focused on characterising throughfall and transpiration processes under various management approaches and climate change scenarios. However, little is currently understood about the soil hydrological processes which serve as a link to throughfall and transpiration. We monitored the soil properties, soil water repellency and hydraulic conductivity in a 5, 12 and >30 year old cocoa plantation in the wet and dry seasons. During the wet season repellent conditions were absent in all stands while the hydraulic conductivity showed no significant differences among them. This suggests that stand age has little effect on water movement during the wet period. During the dry season, the soil at the 5 and 12 year old stands became extremely repellent and was twice as severe as that of the >30 year old plantation. It was expected that the extreme repellency in the younger stands would reduce infiltration rates; however, higher rates were recorded in the 5 and 12 year old stands. This was likely due to the combination of a repellent soil matrix and the presence of large, deep soil cracks which enhanced preferential flow. As the repellency was not significantly correlated with soil properties, we hypothesised that the high grass/sedge cover and temperatures in the 5 and 12 year old stands enhanced it. While further research is needed to investigate the role that grass and sedges play in developing repellent conditions, managing their cover may prove beneficial for the growth and survival of young cocoa trees.