Research article

EFFECT OF MINERAL AND MANURE FERTILIZERS ON PHOSPHORUS LEACHING UNDER DIFFERENT LAND USES IN CALCAREOUS SOILS

Farhad Ali Hashim and Khalida A. Hassan

Online First: March 24, 2023


A study on soil columns was performed to investigate P leaching from calcareous soils under different land uses treated with 200 mg P kg-1 soil as superphosphate (S) or 30 g kg-1 soil as cattle manure (A). The soil samples were incubated for 17 days before the leaching process. Overall, comparison of the five leaching pore volumes showed that the concentration of P in leachates increased in the final pore volumes (PVs) and was higher for soil under vegetable use treated with manure for both locations. The lowest values were recorded for soils amended with superphosphate and uncultivated soils. On comparing the various concentrations of CaCl2, the highest P concentration was found in the leachate of 10 mM of CaCl2 solution. Derabin's P concentration in the leachate was nearly twice that of Batil. The differences in soil properties are the main reasons for the different behaviours of P leaching from both soils. The results showed that all the leachates of all CaCl2 concentrations and different soils were undersaturated with respect to dicalcium phosphate dihydrate (DCPD), dicalcium phosphate (DCP), octacalcium phosphate (OCP), tricalcium phosphate (TCP), and hydroxyapatite (HA) through the leaching process. The saturation index (SI) values for soil treated with superphosphate and uncultivated soil were lower than those cultivated with manure.

Keywords

Phosphorus; incubation; pore volume; saturation index; fertilizers