KINETICS  OF  PHOSPHORUS  RELEASE  FROM    ADDED  ROCK  PHOSPHATE  WITH  SOME  ORGANIC  FERTILIZERS  ON  CALCAREOUS  SOIL.

K.M.Naser,

	KINETICS OF PHOSPHORUS RELEASE FROM ADDED ROCK PHOSPHATE WITH SOME ORGANIC FERTILIZERS ON CALCAREOUS SOIL.
The Iraqi Journal of Agricultural Science
Article 1, Volume 47, Issue 5, 2016, Pages 1305-1312
Author

Abstract
Laboratory experiment was conducted using silty clay loam soil collected from Agriculture fields in Abu Ghraib to study the release of phosphorus from rock phosphate (10.22 P%) on a soil treated with three types of organic fertilizers namely; peat moss , sheep manure , poultry manure and control treatment (soil only). Ten grams of air dried soil mixed with 100 mg of ground rock phosphate and organic fertilizers added at 2.5% level (w:w) were incubated at a laboratory temperature (298 K ) after adding water up to two-thirds of the field capacity for 40, 90, 120, 150 and 180 days. Citric acide soluble available phosphorous was estimated after each incubation periods and kinetic equations used to test its release from treated samples. The additions of chicken manure was the highest in the amount of dissolved phosphorus values followed by sheep manure, peat moss, rock phosphate and control treatment, reaching levels of citric acide extractable phosphorus to 4.2 , 3.8, 3.3, 3.1 and 2.5 mg P kg-1 soil, respectively. The results also showed superiority of first order equation in the description of phosphorus release from rock phosphate with release rate coefficient of 3.801 , 3.865 , 4.328 and 4.366 mg P kg -1 soil h-1 for the treatments: soil and rock phosphate only , peat moss, sheep waste and chicken manure, respectively.
Keywords
Phosphorous release; phosphate rock; organic fertilizers; kinetics equations

Statistics Article View: 161 PDF Download: 61