Spatio-temporal variations of soil properties under cocoa interplanted with kola in a part of the Nigerian cocoa belt

Spatio-temporal variations in soil properties under cocoa interplanted with kola in 15- and 40- ear-old plots were considered in a part of the Nigerian Cocoa Belt. The study shows that no significant variations occur in soil properties when both cocoa and kola are 15 years old. However, significant variations in many soil properties are recorded when cocoa and kola are 40 years old. At that time, soil conditions from sample points directly under kola and between kola and cocoa were similar while soil from the sample point directly under cocoa differed significantly, in most respects, from the other two points. Soil properties appear to improve under kola over time while the converse is the case under cocoa. It is adduced that these differences result from apparent differences in growth habit and nutrient extraction of kola and cocoa over time.