title: Physico-chemical properties and productivity of a Nigerian Typic-Haplustult amended with fresh and burnt rice-mill wastes.
abstract: In order to arrest the declining productivity of the soils in the Abakaliki agro-ecological zone of S.E. Nigeria, four levels (12.5, 25.0, 37.5 and 50.0 Mg ha-1) of fresh (FW) and burnt (BW) rice-mill wastes abundant in the area, and a mixture of the waste + NPK and NPK alone were added to the soil (Typic-Haplustult) to evaluate their immediate and residual effects on the productivity of the soil using maize (Zea mays L.) as a test crop. Results showed a significant reduction in bulk density as well as improvements in total porosity and water stable aggregates (WSA > 0.5 mm) at levels > 12.5 Mg ha-1 of the FW amendments. Although both amendments failed to improve the soil pH, significant improvements in soil C, N and BS were obtained at 37.5 Mg ha-1 and above in both amendments. The highest relative increase (TF) of 135.1% and 102.8% in C and N in the first season and 94.4% and 99.3% in the second season were obtained in the FW at 50.0 Mg ha-1. The highest maize grain yields of 2.74 and 2.66 Mg ha-1 were obtained in the waste + NPK mixtures (FW/BW + NPK) in the first season. The residual yield was highest (1.45 Mg ha-1) in the FW amendment at 50.0 Mg ha-1. The results showed that regular and properly planned applications of these wastes can sustain the productivity of soils in this region.
authors.affiliation: Department of Biological Sciences, Nnamdi Azikiwe University, P.M.B. 5025, Awka, Anambra State, Nigeria. nnabude@enugu.nipost.com.ng
authors.forename: P C
authors.initials: PC
authors.lastname: Nnabude
authors.forename: J S
authors.initials: JS
authors.lastname: Mbagwu
mesh_terms: D002244:Carbon / Q000032:analysis; D018556:Crops, Agricultural / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D004463:Ecology; D005308:Fertilizers; D006863:Hydrogen-Ion Concentration; D009549:Nigeria; D009584:Nitrogen / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis; D012275:Oryza / Q000737:chemistry / Q000378:metabolism*; D016062:Porosity; D012037:Refuse Disposal; D012987:Soil / Q000032:analysis; D014866:Waste Products; D003313:Zea mays / Q000254:growth & development*
chemical_list: D005308:Fertilizers; D009930:Organic Chemicals; D012987:Soil; D014866:Waste Products; D002244:Carbon; D009584:Nitrogen