Reclamation and sustainability of the overmined soybean field at Badeggi, Nigeria.
Gana A. K., Adagba M. A.
Author Affiliation: National Cereals Research Institute P.M.B. 8, Bida, Niger State, Nigeria.
International Journal of Agricultural Technology 9 : 987-997
Abstract : Long-term cultivation of crops in the North central zone of Nigeria, belonging to guinea savanna agro-ecology, has resulted to soil quality degradation that could affect economic development in the region if sustainable production practices are not identified. Over fifteen years, soybean field of the National Cereals Research Institute (NCRI) Badeggi, Niger State, Nigeria have been put into continuous research activities with regular use of inorganic fertilizers to sustain the production. This have led to massive depletion of both soil nutrients particularly the major nutrients including nitrogen(N) and potassium (K), along with high loss of organic matter and cation exchangeable capacity(CEC) thereby, leading to high reduction in the grain yield per hectare of soybeans. From the result of the analyzed soil samples collected, the presence of N and K were generally very low. The soil pH was at neutral level between the ranges of 6.0-7.8 which was very suitable for soybean production. The organic matter and cation exchange capacity were very low. The general textural class of the soil of the experimental field was sandy loam. From profile dug, the A horizon was very fragile with thickness of 14.0 cm, horizon B was 23.5 cm and it was a transition between horizon A and C. The C horizon has thickness of 62.5 cm and it was made up of 100% laterite soil. This soil of soybean field in NCRI Badeggi is to be reclaimed through the use of organic manure particularly cattle dung which is bulky and can improve the organic matter content of soil, and also thereby, increasing the CEC of the soil. Freshly decomposed organic matter should be used mostly as a fertilizer because it contributes more to CEC content than older organic matter. Zero or minimum tillage should be adopted to enable the maintenance of the soil structure. Farming systems such as crop rotation, bush fallowing, organic farming (using organic materials that are rich particularly in phosphate and nitrogen) and agro-forestry involving the use of trees or shrubs such as acacia (Acacia spp.) shear butter (Buttyrospermum paradoxi), locust bean (Parkia clappertonia), mango (Mangifera indica), guava (Psidium guajava), tamarind (Tamarindus indica) should be practiced to enable the achievement of soil sustainability.