THE IMPACT OF ARBUSCULAR MYCORRHIZAS FUNGI (AMF), IDOLE-3-ACETIC (IAA), AND NPK ON SOIL CHEMICAL PROPERTIES AND GROWTH OF CASSAVA IN OKITIPUPA, SOUTHWEST, NIGERIA

Conventional agricultural practices mainly rely on agronomic measures and chemical inputs to improve nutrient use efficiency (NUE) which could lead to soil degradation and loss of biodiversity, with detrimental consequences for soil health and ecosystem functioning. This study aims to evaluate the impact of Indole-3-Acetic Acid (IAA), Arbuscular Mycorrhizal Fungi (AMF) as inoculants in combination with NPK doses on soil chemical properties and cassava yield in Okitipua between April to August 2014, Southwest Nigeria. There were five treatments   namely, Arbuscular mycorrhizal Fungi, idole-3-acetic (1g), NPK 15:15:15 fertilizer (300kg/ha), Abuscular mycorrhizal Fungi + NPK. 15:15:15 fertilizer and control, the experimental design was Randomized Complete Block Design (RCBD). The results were subjected to statistical analysis using SPSS. AMF showed low impact on the soil from the experimental site. It has showed effect on few soil parameters (Soil pH, TOC, Na+, Mg2+ and base saturation). The addition of NPK to the soil showed positive impact in some soil parameters such as TOC, Na+, K+, Ca2+, Mg2+ and base saturation. The combination of NPK and AMF (NPK+AMF) has shown more impact in most soil parameters such as TOC, Na, Na+, Ca2+, Mg2+, base saturation and Mn. NPK, AMF, and the combination of NPK, NPK + AMF have shown impact in the growth of cassava by increasing the height of the cassava plant. NPK, IAA, and NPK+AMF have shown impact in the leaves by the increase in the number of leaves. Only NPK, NPK + AMF had shown impact on the stem of the cassava by increasing the number of stems in all weeks after planting (WAP). The stem diameter shows significant increase from week 1 to week 6 with the help of the applications of NPK and NPK+AMF. This research gives information on the use and benefits of AMF, AMF + NPK in a appropriate proportion to grow cassava in Okitipupa and its environs. If properly managed, it is a promising step to reduce the total dependence on the mineral fertilizers for the growth of cassava in the study area.