Abstract
Phosphate sorption studies were conducted on Rustum, Miani and Sultanpur soil series at 25 and 35 ± 1°C and incubation periods of 1 to 60 days with phosphorus levels from 2.5 to 1000 µg g־¹ soil. For Rustum soil series after the incubation of 1 and 60 days; incubation temperature of 25± 1°C and phosphorus levels of 2.5 and 1000.0 µg g־¹ soil the phosphate sorption was 0.5 and 363.0 and 943.0 µg g־¹ soil, respectively and at the incubation temperature of 35 ± 1°C the phosphate sorption for same phosphorus levels and incubation period was 1.8 and 2.0 and 485.0 and 987.0 µg g־¹ soil, respectively. For Miani soil series after the incubation of 1 and 60 days; incubation temperature of 25 ± 1°C and phosphorus level of 2.5 and 1000.0 µg g־¹ soil, the phosphate sorption was 0.7 and 0.8 and 320.0 and 941.0 µg g־¹ soil, respectively and at the incubation temperature of 35 ± 1°C the phosphate sorption for same phosphorus levels and incubation period was 1.0 and 1.3 and 465.0 and 986.0 µg g־¹ soil, respectively. For Sultanpur soil series after the incubation of 1 and 60 days; incubation temperature of 25 ± 1°C and phosphorus level of 2.5 and 1000.0 µg g־¹ soil the phosphate sorption was 0.3 and 0.8 and 293.0 and 949.0 µg g־¹ soil, respectively and at the incubation temperature of 35 ± 1°C the phosphate sorption for same phosphorus levels and incubation period was 1.2 and 1.4 and 452.0 and 983.0 µg g־¹ soil, respectively. The results demonstrated that the increasing phosphorus levels, higher incubation temperature and increasing incubation period resulted in higher phosphate sorption for the same soil series. The phosphate sorption by soil series was of the order: Rustum> Miani> Sultanpur, for both the phosphorus levels and incubation temperatures.
