Impact of Arbuscular Mycorrhizal Fungi (AMF) on nutrient uptake and the growth of C. retusa and S. occidentalis under phosphorus stress

This study investigates the influence of Arbuscular Mycorrhizal Fungi (AMF) on the growth of Crotallaria retusa and Senna occidentalis under three phosphorus levels (low, medium, and high). Conducted in the experimental garden of Ahmadu Bello University Zaria, the soil samples were collected from a degraded site at the Institute of Agricultural Research, sieved, and sterilized. Perforated buckets were filled with sterilized soil, and the trench method was employed for AMF application. Three phosphorus levels were tested, and seeds of C. retusa and S. occidentalis were planted in individual buckets. Daily watering and observations were carried out for twelve weeks, measuring seedling height, leaf length, width, and number of leaves. The results indicate that high phosphorus concentration (12g/bucket) constrains the growth of C. retusa, while medium concentration (6g/bucket) enhances shoot length, branches, and leaves. AMF inoculation significantly improves growth attributes, but reduced growth in C. retusa under high phosphorus suggests potential incompatibility between phosphorus and AMF. At week 6, medium phosphorus (6g/bucket) resulted in more leaves (122.17±37.61) than low and high levels. Lowest growth occurred at low phosphorus (0g/bucket). Arbuscular mycorrhizal fungi improved overall growth, but high phosphorus hindered C. retusa growth due to potential incompatibility with AMF. Overall, the study highlights the complex interplay between AMF, phosphorus levels, and plant growth, offering insights into optimizing conditions for the cultivation of C. retusa and S. occidentalis.