127-12 Phosphorus Determination In Long-Term No-Tillage Rotation Study.



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Catherine Fleming1, Mark Reiter1, Rory Maguire2, Jason Warren3 and Steve Phillips4, (1)Virginia Polytechnic Institute and State University, Painter, VA
(2)Virginia Tech, Rural Retreat, VA
(3)Oklahoma State University, Stillwater, OK
(4)International Plant Nutrition Institute, Owens Cross Roads, AL
Continuous no-tillage wheat, corn, and soybean systems are commonplace in the Mid-Atlantic region. Conservation tillage affects soil properties throughout the horizon due to a lack of soil mixing. The focus of this study is to compare long-term, no-tilled soils that have received no P fertilizer (control), inorganic P fertilizer (soil test P, STP), non-amended poultry litter (PL), and poultry litter amended with alum (PLA). A long-term no-till rotation (corn – wheat – soybean – fallow – corn) 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 (approximately 120 kg N ha-1) to wheat and 11.2 Mg ha-1 (approximately 200 kg N ha-1) prior to corn planting. The STP 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, and 2010. Soils were analyzed for pH and Mehlich 1 extractable P (M1-P). In 2000, there were no significant differences in pH (average = 6.19; p = 0.3887). By 2010, there were no significant differences between treatment pH (average = 5.09; p = 0.2000); however, the PL and PLA treatments had generally higher pH (5.11 and 5.30, respectively) than STP and no-P control treatments (4.91 and 5.05, respectively). In 2000, there were no significant differences in M1-P (average = 95 mg P kg-1; p = 0.8738). However, by 2010, PLA had higher M1-P than PL (273 and 187 mg P kg-1; p = <0.0001). Both the no-P control and STP treatments were lower (83 and 102 mg P kg-1) than both PL treatments. In conclusion, in a long-term no-till system, amending PL with alum will increase Mehlich-1 extractable P compared to non-amended PL, but does not seem to significantly impact overall soil pH.
See more from this Division: S04 Soil Fertility & Plant Nutrition
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