Effects of Selected Leguminous Crops on the Physical and Chemical Characteristics of Ultisols in Port-Harcourt, Nigeria

The use of leguminous plants are considered a good management practice in any agricultural production system because it can increase cropping system sustainability by reducing soil erosion and ameliorating soil physical, chemical and biological conditions as well as nutrients are made available to the crops. A potted experiment was carried out in a screen house situated in the Rivers State University Teaching and Research Farm to examine the effects of three leguminous crops viz; brown beans (Phaseolus vulgaris), groundnuts (Arachis hypogaea L.) and velvet beans (Mucuna pruriens) on the physical and chemical properties of the soil. Three (3) seeds of each legume was planted in a pot containing ten (10kg) of top soil and replicated thrice. Soil samples were collected from experimental pots before planting and after harvest giving a total of 24 samples which were analyzed for selected physical and chemical properties using standard methods of analysis. The study showed that the three leguminous crops used improved the fertility status of the soil. However, the soils treated with groundnuts appeared to have shown more effects on the soil properties. There was no significant difference in the values for potassium (K) among the treatments. There was an increase in the nitrogen level of soil among the treatment which indicates nitrogen fixation. Ultisols treated with groundnuts showed more positive effects on the chemical properties of the soil after harvest, hence it’s recommended for farmers to intercrop with groundnuts.