Abstract:
A study was conducted to evaluate the potential of organic amendments in
managing sodic soils for crop production. Soils sampled from Cape Coast
industrial area, opposite Ameen Sangari Industries Limited, were used in the
study. In preliminary studies, wastewater discharged from the soap making
industry contained pH of 11.2, EC of 4.37 dS m-1 and ESP of 60.4. Soil used in
the study had the following properties: pH of 8.7, EC of 3.7dS m'1 and ESP of
18.0. A pot experiment was then conducted in which saw dust biochar (SDB),
palm fiber biochar (PFB), poultry manure biochar (PMB) and poultry manure
(PM) were applied to the sodic soil. Gypsum amendment and a control (soil only)
were included for the purpose of comparing results. All amendments were applied
at the rate of 4.78 t ha-1. Amended soils were incubated at room temperature. The
incubated soil was weekly sampled for 6-weeks for laboratory analysis. From the
results, organic based amendments reduced soil pH and electrical conductivity
(EC). The same amendments significantly (P = 0.05) increased soil Ca+2 and
Mg+2, with SDB registering the highest increase. Increases soil Na+ and K+ were
marginal and statistically insignificant (P = 0.05). PFB recorded the highest CEC
at week 6. SDB and PFB reduced soil sodicity below the minimum threshold of
ESP 15. SDB recorded the highest OC increase at week 6. PMB released the
highest amount of available P. Insignificant (P = 0.05) increases were observed
for soil NH4+-N and NO3乙N. SDB and PFB recorded 90 % and 80 % maize seed
germination and also, 10.1 t ha'1 and 8.7 t ha'1 dry matter yields respectively. No
maize seed however germinated in the control and all other amendments.
