Evaluation of Rhizobium inoculation in combination with phosphorus and nitrogen fertilization on groundnut growth and yield

Abstract

Background and Objective: Low soil fertility status, nutritional imbalance and inappropriate agronomic practices are the major problems limiting the current production and yield of groundnut, therefore, a study was conducted during 2015/2016 at the greenhouse of the Universiti Kebangsaan Malaysia (UKM), Bangi, Malaysia, to evaluate the effect of Rhizobium inoculation, in combination with Phosphorus (P) and Nitrogen (N) fertilization on the growth and yield of groundnut. Methodology: The experiment included plots with and without Rhizobium inoculated treatments, two rates of Phosphorus (P) fertilizer (0.82 kg ha-1) and two rates of Nitrogen (N) fertilizer (0.27 kg ha-1). The treatments were laid out in a split-split plot design with two main plots (plots with and without Rhizobium), two subplots (for two nitrogen levels), two sub-sub-plots (for two phosphorus levels) and the experiment replicated thrice. Results: The highest growth and yield parameters such as maximum plant height (75 cm), number of branches (21.3 per plant), number of nodules (45 per plant), number of pods (18.3 per plant), pod yield (2661.7 kg ha-1), 100 seed weight (39.2 g), shelling percentage (43.1%), oil content (54.3%), protein content (25.6%), seed moisture (7.9%) and seed germination (86%) were observed in artificially inoculated Rhizobium treatment plots where the recommended dosage of inorganic P and N fertilizers were applied. Conclusion: Based on the results of the study it can be tentatively concluded that groundnut seed inoculated with Rhizobium and subsequently fertilized with P2O5 and N at rates of 82 and 27 kg ha-1, respectively during the growth stage showed improved growth and yield parameters.