Okpamen SU, Omoruyi E, Aondona
Abstract
This experiment documents and evaluates the nutrient status in four soils in the coconut belts of Nigeria. It also studies the info-yield and nutrient data available on various soils in coconut belts of Nigeria. Data on nutrients are collated separately from four specific soils, sampled and tested for nutrient elements and physical parameters; these include Coastal marine soil, Inland forest soil, Inland savannah soil and Coastal alluvium soil. Other parameters compiled in this study are the progeny yield performances of indigenous and exotic hybrids of coconuts and nutrient uptake from soils by the palm. This work statistically compares the nutrients in the four soils to ascertain the soil-nutrient adequate for coconut cultivation and distribution using regression analysis. It was established from the results that nutrients in the four soils were in the order of coastal marine soil > inland savannah soil > coastal alluvium soil > inland forest soil. The distribution of clay fraction was in the order of coastal alluvium soil > inland savannah soil > inland forest soil > coastal marine soil. For nutrient such as Available phosphorus, Exchangeable Magnesium, and Potassium, were higher in the inland savannah soil, while Exchangeable sodium, (Exch.Na) and Total Sulphur were higher in coastal marine soil. The results on nutrient uptake revealed that Exch. Na and total soil Sulphur affects yield of coconut significantly. And a correlation of Sodium (Na) across the four soils revealed a significant positive correlation with inland forest soil r=0.961 and negatively with coastal alluvium soil r=-0.814. The distribution of calcium was in the order of coastal alluvium soil > coastal marine soil > inland savannah soil > inland forest soil. Calcium is indeed a very vital element for coconut development and rates of uptake was high and tend to be higher in soils of the coastlines (coastal alluvium and marine sand soils). Although the nutrients in the four soil varied ,but on the average the correlation result from the soil nutrient suitability index revealed that coaster marine sand and inland savannah soils contains the highest nutrients for coconut development, While coaster alluvium and inland forest soils though may have vast population of coconut palms does not contain as much nutrients as the former All findings however are without prejudice to earlier results of other literatures on soils of coconut palms in Nigeria.