THE EFFECTS OF ORGANIC FERTILIZERS ON GROWTH OF RHIZOBACTERIA AND CULTIVATION OF CORN IN WETLAND SOILS OF AKWA IBOM STATE

Abstract

The effects of organic fertilizers on rhizobacterial growth and maize cultivation in wetland soils of Akwa Ibom State were evaluated. Poultry droppings and cattle dung were assessed for their nutrient compositions, influence on soil fertility, microbial populations, and maize yield using standard techniques. Physicochemical analysis revealed that composted poultry manure (PM) contained higher nutrient values (pH 7.25, organic carbon, OC 32.8%, nitrogen 2.87%, phosphorus 121 mg kg⁻¹, and potassium 1.82 cmol kg⁻¹) than cattle manure ,CM (pH 6.78, OC 28.5%, N 2.23%, P 96 mg kg⁻¹, K 1.35 cmol kg⁻¹). Baseline soil pH averaged 5.55, indicating moderate acidity. PM indicated increased soil pH (6.23), total N (0.26%), available P (14.9 mg kg⁻¹), and OC (2.53%); highest rhizobacterial counts (2.58×10⁶ CFU g⁻¹ total bacteria; 4.9×10⁴ CFU g⁻¹ Azotobacter chroococcum ; 3.8×10⁴ CFU g⁻¹ Pseudomonas pseudo-alcaligenes kv9) enhanced rhizospheric activity as well as improved maize growth and yield with plant height, leaf length and grain yield (111.2, 59.3 cm and 3.85 t ha⁻¹) respectively. Positive correlations (r = 0.90–0.93; p < 0.005) were observed between microbial abundance and plant performance. Identified bacterial isolates included Azotobacter sp. (98.7%) and Pseudomonas pseudoalcaligenes kv9 (99.1%), confirming their role in bio-fertilization. Overall, PM proved superior to CM in improving soil fertility, rhizobacterial activity, and maize productivity in wetland soils.