Evaluation of Soil Temperature, Water Productivity and Agronomic Performance of Potato (Solanum Tuberosum L.)-Legume Intercropping System in the Western Highlands of Cameroon

ABSTRACT

Intercropping is a farming practice involving two or more crop species, growing simultaneously in the same area and which could efficiently utilize natural resources. A two-year study was conducted during 2021 and 2022 in the western highlands of Cameroon to examine the impacts of potato-legume intercropped on soil water content (SWC), productivity and  soil  temperature(ST) in order to identify cropping systems (CS) that controls ST  and water productivity (WP). A randomised complete block design with seven treatments: sole potato crop (T1), Mucuna (T2), lima bean (T3), cowpea (T4) and intercropping systems of Mucuna+potato (T5), lima bean+potato (T6) and cowpea+potato (T7) was used. CS has a significant effect (P<0.05) on ST with the lowest ST being obtained in T5 (19.50°C), T7 (19.66°C) and T6 (19.68°C) against 20.20°C in T1. SWC varied with CS (P<0.05) with T1 having the lowest SWC of 40% versus T5 (47.90%), T6 (44.42%) and T7 (42.76%). Water use increased significantly (P<0.05) with T1 (783.34mm) and decreased from T7 (783.32mm) to T5 (783.30mm). As for WP, T1 (2.96g.mm-1) recorded the lowest value and T5 (4.04g.mm-1) the highest. T5 had the highest tuber yield (29.60t.ha-1) and T1 the lowest (23.21t.ha-1). Legume grain yield and biomass were highest in T5 (2.10t.ha-1 and 6.78t.ha-1 respectively) compared to others intercropping systems. The intercropping systems obtained an overall LER and WER greater than 1 with the highest in T6 (6.20 and 2.63).  Intercropping potato with Mucuna or lima bean reduces soil temperature while improving soil water productivity that enhances potato production.