Residual Effect of Phosphorus Application Rates on Soybean Nodulation, Post Harvest Soil Properties and Performance of Suceeding Maize

Abstract

Phosphorus is known to be a major nutrient that has significant effect on the growth and nodulation of legumes. A field experiment was conducted at the experimental site of the Federal College of Agriculture, Moor Plantation, Ibadan to determine the residual effect of phosphorus rates on soybean (Glycine max) nodulation, some post harvest soil properties and the performance of Succeeding Maize. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four treatments, each replicated three times. The treatments consisted of different levels of phosphorus fertilizer including 0 kg / ha (control), 20 kg/ha, 40 kg/ha and 60kg/ha. Soybean seeds were sown at the rate of 2 seeds per hole. Parameters taken were; Yield of soybean, Number of Nodules per plant, Weight of Nodules per plot (g), nitrogen fixation by soybean, available phosphorus, organic matter of the post harvest soil the yield and yield component of succeding Maize.The results obtained showed that the treatment of soybean with 60kg /ha of P0O5 gave the highest yield of 979.73kg/ha. Similarly, treatment with 60kg/ha of P0O5 produced the highest nitrogen content (1.40g/kg) and highest organic matter content (24.26g/kg) in the post harvest soil. However, the highest number of nodules were produced by the soybean treated with 20kg/ha of P0O5 (6.08) while the least number of nodules were produced by 60kg/ha of P0O5 (2.92). Succeeding Maize planted on the plot with the highest Phosphorus rate also had the highest grain yield, seed weight and shelling percentage.Phosphorus levels had no significant effect on weight of nodules. It is therefore recommended that 60kg/ha of P0O5 on soybean be implemented for optimum yield of soybean and suceeding maize, more nitrogen fixation by soybean and more organic matter in the post harvest soil.