Effect of using Pseudomonas fluorescens bacteria, Glomus mosseae fungus and liquid organic fertilizer on soil available nitrogen and phosphorus and some characteristics of fenugreek (Trigonella foenum graecum L.) and choline seed content

N.A. Al-Silmawy¹, E.H. Abd², R.F. Shahad³ and R.J. Mohammed⁴

¹Department of Soil Sciences and Water Resources, College of Agriculture, University of Wasit, Iraq
²Department of Desertification Combat, College of Agricultural Engineering Sciences, University of Baghdad, Iraq
³Department of Soil Sciences and Water Resources, College of Agriculture,
Al-Qadisiyah University, Al-Qadisiyah, Iraq
⁴Department of Soil Sciences and Water Resources. College of Agriculture, Al-Qasim Green University, Babylon, Iraq
*Correspondence: nkadhim@uowasit.edu.iq

Abstract:

A factorial pot experiment was conducted during the fall season of 2023–2024 in the fields of the College of Agriculture/University of Wasit, according to a randomized complete block design (RCBD) with three factors and three replicates. The first factor is the bacterial inoculum Pseudomonas fluorescens at two levels (addition B1 and without addition B0), the second factor is the fungal fertilizer Glomus mosseae at two levels (addition M1 and without addition M0), and the third factor is the liquid organic fertilizer at two levels as well (addition O1 and without addition O0) added in two batches, thus we have eight treatments with three replicates so that the number of experimental units is 24 experimental units (pots). Available nitrogen and phosphorus in the soil, plant height, number of branches, number of pods, number of seeds per pod, seed content of active substance choline, and biological yield were measured. The triple interaction treatment of the three factors (B1M1O1) gave the best results for the mentioned traits, followed by the dual interaction treatment between bacteria and fungi (B1M1), then the dual interaction treatments between bacteria and liquid organic fertilizer B1O1 and between fungi and liquid organic fertilizer M1O1, then the single treatments B1, M1, and O1, and finally the control treatment without additives (B0M0O0), which gave the lowest results. The mycorrhizal reliability was calculated for each of the plant heights, number of pods, and biological yield and was 22.2, 68.25, and 33.00%, respectively.

Key words:

Phosphate solubilization potential of indigenous rhizosphere fungi and their biofertilizer formulations

D.A. Balogun¹², M.A. Oke³, L. Rocha-Meneses⁴⁵, O B. Fawole⁶ and P.F. Omojasola¹*

¹Department of Microbiology, Faculty of Life Sciences, University of Ilorin, 1515 Ilorin, Nigeria
²Nigerian Stored Products Research Institute, 1489 Ibadan, Nigeria
³Independent Researcher, Edmonton, AB, Canada. T5X 0H2.
⁴Biomass & Bioenergy Research Group, Center for Sustainable Energy and Power Systems Research, Research Institute of Sciences and Engineering, University of Sharjah, 27272 Sharjah, United Arab Emirates
⁵Institute of Technology, Chair of Biosystems Engineering, Estonian University of Life Sciences, Kreutzwaldi 56, 51006 Tartu, Estonia
⁶Department of Agronomy, Faculty of Agriculture, University of Ilorin, 1515 Ilorin, Nigeria
*Correspondence: jasola@unilorin.edu.ng

Abstract:

The harmful effects of chemical fertilizers on soil, plants, and eco-systems have stimulated the growth of the global biofertilizer market. However, biofertilizer use remains limited in developing countries due to inadequate research and poor technology. The use of readily available materials for biofertilizer production can be a good starting point. This study aimed to investigate phosphate-solubilizing potentials of soil fungi and the shelf-life of their biofertilizer formulations using sawdust and charcoal as carriers. Soil samples from the rhizosphere were cultured on Pikovskaya (PVK) agar, and the best phosphate solubilizers (Aspergillus niger, Aspergillus fumigatus and A. flavus) were screened for their phosphate-solubilization potentials on solid medium. Results obtained showed that A. niger had the highest solubilization index of 1.72, followed by A. fumigatus, and A. flavus with a solubilization index of 1.01 and 0.95, respectively. Optimization studies showed that after 5 days of incubation, A. niger, A. flavus and A. fumigatus solubilized 149, 112 and 126 mg L^-1 of phosphate, respectively. These values increased to 549 mg L^-1 on day 11 for A. niger, 379 mg L^-1 on day 9 for A. flavus and 430 mg L^-1 on day 9 for A. fumigatus. Furthermore, A. fumigatus and A. flavus proved to be better inoculants than A. niger as they maintained higher CFU g^-1 counts throughout the experiment. Also, sawdust supported higher counts of the three inoculants than charcoal and was thus the best carrier. The findings demonstrated that these aspergilli can be harnessed for improving soil fertility and plant development.

Key words:

A. flavus, A. fumigatus, A. niger, biofertilizer, optimization, phosphate solubilization, shelf-life