76997 Phosphorus Fraction Determination On a Long-Term No-till Rotation.

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See more from this Session: Graduate Student Oral Soils
Monday, February 4, 2013: 1:30 PM
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Catherine Fleming, Crop and Soil Environmental Sciences, Virginia Polytechnic Institute and State University Eastern Shore Agricultural Research and Extension Center, Painter, VA, Mark S. Reiter, Eastern Shore Agricultural Research and Extension Center, Virginia Tech, Painter, VA and Rory Maguire, Department of Crop and Soil Environmental Sciences, Virginia Tech, Blacksburg, VA
Continuous no-tillage wheat, corn, and soybean systems are commonplace in the Mid-Atlantic. Conservation tillage impacts soil properties due to a lack of soil mixing. This study compared long-term, no-tilled soils that have received no P fertilizer (control), inorganic P fertilizer (triple super phosphate, TSP), non-amended poultry litter (PL), and poultry litter amended with alum (PLA). A long-term no-till rotation (corn – wheat – soybean – fallow) was initiated in 2003 in Painter, VA on a Bojac sandy loam. Poultry litter treatments (PL and PLA) were applied at 6.7 Mg ha-1 to wheat and 11.2 Mg ha-1 prior to corn planting. The TSP treatment received fertilizer applied as triple super phosphate based on soil testing. Soil samples were taken from 0 to 5 cm from years 2000, 2004, 2008, 2010, and 2011. Additional soil depths (5-15 cm and 15-30 cm) were analyzed for 2004 and 2011. Soils were analyzed via sequential fractionation extractions for loose P, Al bound P, Fe bound P, reductant soluble P (RSP), and Ca bound P. Total inorganic P was also estimated by summation of the fractions. Significant differences in shallow soil samples (0-5 cm) were found in concentrations of loose P after one year of fertilizer application, and continued to have significant differences over time. In 2008, 2010, and 2011, PL and PLA treatments were significantly higher in loose P and Al bound P than the control and TSP treatments. No differences were observed for Fe bound P. PLA was significantly greater in RSP and Ca bound P in 2010. In 2011, total inorganic P was significantly higher in the PL and PLA treatments than the control and TSP treatments. Few differences were seen in soil P fractions in samples below 5 cm. In conclusion, alum additions can reduce loose P at 0-5 cm.
See more from this Division: Submissions
See more from this Session: Graduate Student Oral Soils