Kinetics of Phosphorus Release in Coastal Plain Sand Soils Amended with Animal Manure in Akwa Ibom State, Nigeria
Author(s):
Umoh F. O. | Umoinyang A. T. and Ekwere O. J.
Journal:
Academians Journal of Biology
Abstract
This study was carried out to assess Phosphorus (P) release on coastal plain sand soils amended with Poultry, Goat and Pig manures which was grown with soybean, using three Kinetic models, Soil physicochemical properties were also determine, the data on P released were fitted to models . The results show that applications of animal manure did not change the texture of the soils which was loamy sand. Soils amended with animal manures increased soil pH when compared to unamended soils. The values ranged from 4.40 to 5.60 (Pig manure) > 4.40 to 5.20 (Goat manure) > 4.40 to 5.00 (Poultry manure). The mean pH was 4.82 higher than the control being 4.40. Electrical conductivity was higher than the control by 2%, Organic matter content was higher in the amended soils with a mean of 4.20% compared to unamended soil with a value of 3.76%. Total Nitrogen was higher than control by 2%, available P ranged from 6.20mgkg-¹ in control to a mean of 6.76mgkg-¹. The Cation Exchange Capacity of the soil were slightly higher than the control. The order of abundance ranged from Calcium (2.16 cmolkg-¹) > Potassium (1.00 cmolkg-¹) > Magnesium (0.28 cmolkg-¹) > Sodium (0.09 cmolkg-¹), Exchange acidity value decreases with the rates of application of manure. The mean values ranged from 1.48 cmolkg-¹ (Control) to 1.43 cmolkg-¹ (amended soil). Effective cation exchange capacity and percentage base saturation also increases. The results also revealed that soils amended with animal manure released more P than unamended soils. The trend was: Pig manure ranged from 13 to 29.6 (mgkg-¹) > Goat manure ranged from 13.5 to 26.9 (mgkg-¹) > Poultry manure ranged from 13.5 to 24.3 (mgkg-¹) in Elovich model. Pig manure ranged from 2.61 to 3.39 (mgkg-¹) > Poultry manure ranged from 2.60 to 3.30 (mgkg-¹) > Goat manure ranged from 2.61 to 3.19 (mgkg-¹) in Power function model. Pig manure ranged from 0.06 to 0.08 (mgkg-¹) > Poultry manure ranged from 0.05 to 0.08 (mgkg-¹) > Goat manure ranged from 0.03 to 0.08 (mgkg-¹) in Parabolic diffusion. The concentration of P release increased with increasing time of extraction, the hours of 120 recorded the highest concentration. It also indicated that concentration of P released significantly correlated with Soil pH, OM, P, K, Ca, Mg, BS, Silt and Clay. Elovich model successfully described the P released in the soils with the highest R² values of 0.999 and is therefore recommended to be used for the soils.
Keywords:
coastal plain sand, phosphorus, kinetic models, animal manure and soil properties