Impact of municipal compost on soil phosphorus availability and mineral phosphorus fractions in some calcareous soils
A.R.Hosseinpur, S.; Kiani, M.Halvaei
Environmental Earth Sciences 67(1): 91-96
ISSN/ISBN: 1866-6280 DOI: 10.1007/s12665-011-1482-1
The phosphorus (P) resources worldwide are limited, and the prices of commercial P fertilizer continue to increase. Therefore, the use of P containing wastes is important for P recycling in agriculture. The P fractionation methods have been widely applied to characterize the effect of land use practice on soil P dynamics. Information about effect of organic manures on available P and inorganic P (Pi) fractions in calcareous soils of Chaharmahal va Bakhtiari province is limited. The objectives of this research were to study the effect of municipal compost (MC) on available P and Pi forms in five calcareous soils. Municipal compost was applied at the rates of , .5, 1., 1.5 and 2.% (w/w). Samples were incubated at 25 1 C and 2% moisture content for 15 days. At the end of incubation, available P in MC-treated soils was extracted by Olsen, AB-DTPA and .1 M CaCl2 methods. Also, phosphorus was fractionated chemically into labile P (LP), non-occluded P(NP), re-adsorbed P (RP), occluded P (OP), calcium phosphates (CaP) and residual P. The results showed that there was a linear increase in soil available P with MC application. There was a significant positive relationship between Olsen-P, AB-DTPA-P and .1 M CaCl2-P, and MC additions with slopes ranged from .471 to .583, .32 to .16, and .33 to .81, respectively. The increase in soil test P (STP) from MC additions was not related to the initial STP of the soils. A sharp increase in LP, NP and CaP and decrease in residual P concentration occurred in all soils with MC application. It can be concluded that MC applied to calcareous soils may enhance P nutrition of plants. Furthermore, applied P partitioning into the relatively available forms means the potential erosion losses of P to streams and other bodies of water.