Soil Organic Matter Effects on Phosphorus Sorption: A Path Analysis
2009
Kang, Jihoon | Hesterberg, Dean | Osmond, Deanna L.
While P sorption in mineral soils has been extensively studied, P sorption behavior in organic-rich soils is less known. This study was conducted to determine the relationships between Langmuir P sorption maxima (S ₘₐₓ) and selected physicochemical properties of soils, with particular emphasis on organic matter (OM) content. The S ₘₐₓ values were determined for 72 soil samples from the North Carolina Coastal Plain, along with pH, clay and OM contents, oxalate-extractable P (Pₒₓ), Al (Alₒₓ), and Fe (Feₒₓ), and Mehlich 3 extractable P (PM₃), Al (AlM₃), and Fe (FeM₃). Path analysis was used to examine direct and indirect effects of soil properties on S ₘₐₓ In the oxalate path analysis, the direct effects of clay, Alₒₓ, and Feₒₓ on S ₘₐₓ were significant in the order Alₒₓ > clay > Feₒₓ (P < 0.05). The S ₘₐₓ was highly influenced by the indirect effect of Alₒₓ and Feₒₓ through OM content. A two-piece segmented linear relationship existed between S ₘₐₓ and OM and the regression slope in soils with OM ≤ 49 g kg⁻¹ was 10-fold greater than that for soils with OM > 49 g kg⁻¹ This finding suggested that noncrystalline or organically bound Al and Fe in the soils with OM > 49 g kg⁻¹ is less effective for P sorption than in the soils with lower OM content. In the Mehlich 3 path analysis, the direct effects of clay, OM, and AlM₃ on S ₘₐₓ were significant in the order AlM₃ > OM > clay (P < 0.05) while the direct effect of FeM₃ on S ₘₐₓ was not significant. Oxalate may be better suited than Mehlich 3 as an extractant for predicting P sorption capacity in the Coastal Plain soils.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
تم تزويد هذا السجل من قبل National Agricultural Library