Asian Journal of Soil Science and Plant Nutrition

A study was conducted to investigate effect of phosphorus on soil properties, cowpea and African yam beans grown in Akwa Ibom State, Nigeria. The site selection was a flat land of 20 m X 17 m for the cultivation of cowpea and African yam beans. The bed measured 4 m in length and 1.8 m in width was raised. Spacing between plots was 1 m and plant spacing was 40 cm × 60 cm. Phosphorus was applied at the rates of 0 kg, 45 kg, 65 kg, and 85 kg. Pha^-1. The experiment was laid down in a randomized complete block design (RCBD) in 3 replicates. The plots measures 21 m in length and 17 m in width having a total of 38 m × 38 m being 76 m. Soil samples were collected before and after the experiment. Also plant data were taken, Plant height was measured and taken randomly every fortnight. Data collected were subjected to analysis of variance (ANOVA) at p = 0.05 %. Results showed that soils in the study area were predominantly sand. Before planting, sand was 90.70 %, while silt and clay percentages were 3.20 % and 6.10 % respectively. The low organic matter content, 2.00 % could be due to the effect of soil erosion, leaching and bush burning predominant in the study area. At 40 kg. P ha¹ of phosphorus rate, the highest significant stem girth (1.4 cm) was found in white cowpea, while the lowest significant stem girth (0.6 cm) was found in African Yam Bean. It was concluded that African yam beans showed excellent vegetative growth but have a longer duration of maturity. Triple super phosphate application at 40 kg. P ha^-1 recorded the best yield in white cowpea.