ABSTRACT
Loblolly pine (Pinus taeda L.) grown on infertile coastal plain soils typically shows a growth response to N and P applied at mid-rotation. The objectives of this study were to determine whether less soluble poultry litter ash (PLA) provides an adequate supply of P compared to triple superphosphate (TSP), and assess effects on P mineralization and runoff loss. Effects of 56 kg P ha−1 as either PLA or TSP, and no fertilization were compared using an 11-year-old stand of two loblolly pine genotypes on a loamy sand in a completely randomized design. Tree height, diameter and foliar nutrients, soil Mehlich 3 P and phosphatase activity (A and E horizons), and P in surface runoff were monitored. Through more than two years, P fertilization had no effect on tree growth. Similar foliar P with PLA or TSP, together with increasing foliar and soil P over time, suggested that PLA is an adequate source of P for loblolly pine. Neither fertilizer suppressed P mineralization as measured by phosphatase activity. The advantage of PLA compared to TSP is potentially much less runoff P loss.
Acknowledgements
This work was supported by the Louisiana Board of Regents under LEQSF [2012-2015]-RD-A-01, with additional funding from the USDA-NIFA. It is a revision of a chapter from:
Vance, C.L. 2019. Using Poultry Litter Ash as a Fertilizer Source for Bermudagrass (Cynodon dactylon) Establishment and Loblolly Pine (Pinus taeda) Plantation. LSU Doctoral Dissertations. 5099.
https://digitalcommons.lsu.edu/gradschool_dissertations/5099
Disclosure statement
No potential conflict of interest was reported by the author(s).