Cation exchange capacity (CEC) is a good indicator of soil productivity and is useful for making recommendations of phosphorus, potassium, and magnesium for soils of different textures. Soil water holding capacity (SWHC) defines the ability of a soil to hold water at a particular time of the season. This research predicted CEC and SWHC of soils using pedotransfer models developed (using Minitab 17 statistical software) from basic soil properties (Sand(S), Clay(C), soil pH, soil organic carbon (SOC)) and verify the model by comparing the relationship between measured and estimated (obtained by PTFs) CEC and SWHC in the Forest Vegetative Zone of Nigeria. For this study, a total of 105 sampling points in 35 different locations were sampled in the study areas. Three sampling points were randomly selected per location and three undisturbed samples were collected at each sampling point. The results showed success in predicting CEC and SWHC from basic soil properties. In this study, five linear regression models for predicting soil CEC and seven linear regression models for predicting SWHC from some soil physical and chemical properties were suggested. Model 5 [CEC =-13.93+2.645 pH +0.0446 C (%)+2.267 SOC (%)] was best for predicting CEC while model 12 [SWHC (%)=36.0-0.215 S (%)+0.113 C (%)+10.36 SOC (%)] is the most acceptable model for predicting SWHC.

No abstract

Effects of thermal and non-thermal pre-processing methods on the physical parameters of jackbean seed were investigated. The bean was subjected to three pre-processing methods roasting and autoclaving which are thermal and sprouting a non-thermal pre-processing method. The physical parameters evaluated include length, width and thickness which were done by the use of digital venier caliper, sphericity index by the use of formula and aspect ratio which is the ratio between length and width. The results of physical characterization revealed that all the pre-processing methods used had effects on the seed. With roasting, there was decrease in all these parameters except sphericity index: length 19.00-15.00 mm, width 13.00-11.00 mm, thickness 10.75-10.55 mm and sphericity index 72.88-80.20 %. The aspect ratio decreased with pre-processing time for all the treatments used from 1.46-1.33. Kernel density (g/cm 3), bulk density (g/cm 3) and density ratio for the untreated seed were 1.24, 0.73 and 0.59 respectively. However, with autoclaving and sprouting, there was increase in length from 19.00-24.00 mm, width 13.00-18.00 mm, thickness 10.75-11.10 mm but a decrease in sphericity index (72.88-67.46 %) as the pre-processing time increased. These results are very useful in designing of processing equipment for the jackbean seeds thus, encouraging the industrial utilization of the seed.