Suitability of Idi-Apa Oke-Oyi Soil for Groundnut Cultivation

Abstract
Soil supplies most of the mineral nutrients for plant growth through the plant’s root system. The need to determine the soil nutrient supplying capacity of the soil at Idi-Apa, Oke-Oyi area of Kwara State, Nigeria for groundnut cultivation is of major concern before embarking on large-scale cultivation of groundnut to avoid great loss. The project was therefore conducted to analyse the soil at Idi-Apa, Oke-Oyi area based on the fertility for the cultivation of groundnut. Soil samples were taken at depths 0–30 cm and 30–60 cm (which is the maximum rooting depth for groundnut) from the land. The samples which were collected through the random method were sent to the laboratory and analysed for chemical parameters: pH; organic carbon (OC); organic matter (OM); calcium (Ca); magnesium (Mg); sodium (Na); potassium (K); and nitrogen (N). Physical properties (textural class) and other properties such as sodium adsorption ratio (SAR); exchangeable sodium percentage (ESP); base saturation (BS) and cation exchange capacity (CEC) were determined. The result of the analysis showed that the pH (7.1-7.8), OM (2.36-6.93%), OC (1.37-4.98%), Na (0.04-0.15%), ESP (1.04 – 1.28%) and BS (95.37-95.85%) were found to be in the range of the requirements for groundnut production, while the other analyses parameters were outside the required range. Generally, some of the major nutrients like and potassium needed by the crop have deteriorated while some others like calcium are available in sufficient quantities. This calls for the application of fertilizer to the soil to provide the lost nutrients and proper monitoring of the soil before the cultivation of groundnut. An integrated approach that involves the cultivation of nutrient-efficient varieties of groundnut on nutrient-deficient soils is suggested. In the absence of magnesium-efficient varieties, the application of magnesium as fertilizer is recommended. There were no significant differences (p >.05) in the results between the two soil layers for all chemical properties considered except for organic where OM was significantly higher in the subsoil than in the topsoil.