Loblolly Pine Mid-Rotation Phosphorus Fertilization with Poultry Litter Ash or Triple Superphosphate

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.

KEYWORDS:

• Phosphorus
• Pinus taeda
• poultry litter ash
• runoff

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).

Additional information

Funding

The work was supported by the National Institute of Food and Agriculture Louisiana Board of Regents [LEQSF [2012–2015]-RD-A-01].