Magnitude, Duration, and Economic Analysis of Loblolly Pine Growth Response Following Bedding and Phosphorus Fertilization

Abstract

Thirteen-year growth of planted loblolly pine (Pinus taeda L.) was examined on 9 poorly drained Lower Coastal Plain sites following bedding and/or application of phosphorus (P) at time of planting. Fertilization dramatically increased height and diameter growth during the first 13 years on all 9 study sites. Height and diameter growth were consistently better in fertilized and bedded plots than in flat-planted, bed-only, and fertilizer-only plots. Comparisons of height growth curves indicate that differences between fertilized and nonfertilized plots are continuing. Foliar and soil P levels in fertilized plots at age 13 suggest that growth on these sites may be increased by additional applications of P. Projection of response to rotation age indicates that the combination of fertilization and bedding results in the greatest total cubic-foot volume and after-tax net present value. South. J. Appl. For. 10:124-28, Aug. 1986.

Silvicultural Treatments to Enhance Productivity

“…Height growth responses to bedding range from 1 to 3 m and are usually achieved early in the rota-tion (Gent et al 1986). Responses are typically the greatest on poorly drained clays and diminish as soil texture grades from clay to loam to sand and as drainage improves.…”

“…Much attention has been focused on ameliorating the gross and highly visual deficiencies of P and B. Long-term volume gains range from 3 to over 10 m 3 ha -1 year -1 on severely deficient sites (Ballard 1972;Flinn et al 1979b;Pritchett & Comerford 1982;Gent et al 1986;Turner & Lambert 1988). Where labour costs are low, fertilizers are typically applied by hand either on the surface, in holes, or in shallow trenches surrounding the seedlings.…”

Using microdialysis to assess soil diffusive P and translocated sap flow P concentrations in Southern Pinus taeda plantations

“…In P-limited sites where soil supply cannot meet plant demand, fertilization is used to substitute for the de cit. P fertilization in Pinus taeda L. stands on the Atlantic Coastal Plain has been shown to bene t growth in P-de cient soils (Pritchett & Swinford 1961;Gent et al 1986) and has become common practice in plantation management (Fox et al 2011). It has been estimated that almost 80% of applied P as fertilization is quickly sequestered away into insoluble forms, leaving the remaining P either in solution or taken up by the trees for immediate use (Holford 1997).…”

Soil properties in site prepared loblolly pine (Pinus taeda L.) stands 25 years after wet weather harvesting in the lower Atlantic coastal plain

“…Bedding and disking have traditionally been prescribed in the Southeastern U.S. to augment or mitigate soil properties and site productivity, and short term benefits of bedding and variable results of disking have been reported (Aust et al, 1998b;Gent et al, 1984Gent et al, , 1983Hatchell, 1981;Mann and Derr, 1970;McKee and Shoulders, 1974;Pritchett, 1979;Xu et al, 2002). Long term effects of bedding on forest productivity are also widely reported (Gent et al, 1986;McKee and Hatchell, 1986;McKee and Wilhite, 1986;Passauer et al, 2013;Tiarks and Haywood, 1996;Wilhite and Jones, 1981); however; few studies report the long term effects of mechanical site preparation on soil properties (Kyle et al, 2005;Lang et al, 2016). Evaluating how soil properties change over time allows for understanding of factors controlling forest productivity such that management prescriptions can be made precisely, efficiently, and sustainably to fulfill the growing demand for forest ecosystem services (Burger, 2009).…”