Soil is the medium for all crop production activities and many of the tropical soils especially soils of South Eastern Nigeria show nutrient deficiency problems after only a short period of cultivation because of the fragile nature and prevailing environmental condition. Land available for further crop production purposes in this area is very limited. To offset some of these problems and boast crop production and yields as well as economic returns, farmers use chemical fertilizers extensively on their field. These chemical fertilizers have their attendant problems ranging from non-availability, high cost, and nutrient imbalances to soil acidity. Consumers of agricultural products and farmers are getting more aware of the dangers caused by these chemicals in soil, environment, and health problems in consuming heavily chemically fertilized crops. An alternative to these chemicals is intercropping due to its environmentally friendly approach. Beside the labour management and adequate use of resources available, intercropping system promotes soil fertility maintenance, conservation and balanced nutrient which will improve crop quality and yield. It ensures farmers’ flexibility, reduction against crop failures, weed control and profit maximization. This paper reviews the various contributions of intercropping system to soil fertility enhancement, nutrient recycle, and transfers among intercrop species; its effect on growth and yield of crop species as well as enlightenment on the various terms used to describe the intercropping system.
Key words: Intercropping, nutrient recycle and transfer, sole cropping, soil nutrients.