Residual Effect of Different Phosphorus Sources on Growth and Nodulation of Soybeans in Alfisols

Abstract

A pot experiment was carried out at the screen house of the School of Agriculture and Agricultural Technology, Gidan Kwano campus, Minna during the cropping season of 2020. The research aimed at evaluating the effect and residual effect of different phosphorus sources on the growth and nodulation of soybean. Four seeds of TSB 4810 variety of soybean were planted per pot containing 2 kg of soil collected from 3 locations. A week after sowing plant was thinned to two seedings per pot. This was followed with the application of N, P, K, Mg and micro nutrients -1(B, Mo, Zn). Thereafter, the crop was fertilized as follows: control at 0 kg P ha , -1organic P of bone meal source at 30 kg P ha , inorganic P of Single Super -1 -1Phosphate at 30 kg P ha and AMF Glomus Intaradices (4 g pot ) received by soils obtained from Maikunkele, Maitumbi and Gidan Kwano. Treatments were then arranged in a Completely Randomized Design (CRD) replicated three times. Data collected were subjected to Analysis of Variance (ANOVA). Means were separated using Least Significant Different (LSD). Results obtained at first planting showed that the best shoot and root weights and the second best nodulation characteristics were obtained when organic P of bone meal source was applied. The second planting did not receive fresh doses of fertilizer treatments and the result obtained at the second planting showed that, except for of root weight, inorganic P improved growth and nodulation of the TSB 4810 soybean variety while organic P could not improve any of the growth characteristics compared to the control. Since soybeans performed significantly better at first planting with the application of fertilizer than second planting with residual fertilizer effect. As a recommendation, farmers should therefore apply fresh doses of phosphorus fertilizer yearly.