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Phosphorus Availability and Transformation as Affected by Repeated Phosphorus Additions in an Ultisol.
- Source :
-
Communications in Soil Science & Plant Analysis . 2015, Vol. 46 Issue 15, p1922-1933. 12p. - Publication Year :
- 2015
-
Abstract
- Phosphorus (P) solubility and transformation in soils determine its availability to plants and loss potential to the environment, and soil P dynamics is impacted by fertilization and soil properties. A Ultisol sample was interacted with 20 mg L−1P solution from one to ten times. The P-reacted soils were then analyzed for water-soluble P (0.01 M calcium chloride (CaCl2)–extractable P); plant-available P (Olsen P); ammonium chloride P, aluminum P, iron P (NH4Cl-P, Al-P, Fe-P, respectively); and occluded P (Oc-P). The degree of P saturation (DPS) was calculated from ammonium oxalate–extractable Al, Fe, and P. The amount of P sorbed by the soil was highly correlated with the frequency of P addition with high percentage of P adsorbed initially and gradually decreased as the P addition continued. The relative abundance of the five P fractions in the P-reacted soil was in the order of Fe-P (36.5 percent) > Al-P (35.6 percent) > Oc-P (22.8 percent) > Ca-P (2.7 percent) > NH4Cl-P (2.3 percent). Both Olsen P and CaCl2-P were significantly increased by the repeated P addition process and highly correlated in an exponential function. The DPS was increased above the so-called critical point of 25 percent after the first P saturation process and kept increasing as the P addition continued. The P availability and adsorption in the soil were controlled by soil free and amorphous Al and Fe. The results suggest that repeated P application will build soil P to an excessive level, and consequently result in poor P-use efficiency and high P-loss potential to surface and groundwater. [ABSTRACT FROM PUBLISHER]
Details
- Language :
- English
- ISSN :
- 00103624
- Volume :
- 46
- Issue :
- 15
- Database :
- Academic Search Index
- Journal :
- Communications in Soil Science & Plant Analysis
- Publication Type :
- Academic Journal
- Accession number :
- 108998360
- Full Text :
- https://doi.org/10.1080/00103624.2015.1069305