Influence of fertilization, weed control, and pine litter on loblolly pine growth and productivity and understory plant development through 12 growing seasons

Abstract

On a silt loam soil in central Louisiana, three cultural treatments were applied to a seedling loblolly pine (Pinus taeda L.) plantation. The treatments were in a 2 × 2 × 2 factorial design: (1) no fertilization or a broadcast application of 177 kg N/ha and 151 kg P/ha; (2) no herbicides applied or broadcast or spot applications of hexazinone, sulfometuron methyl, or glyphosate herbicides and felling as required to control competing vegetation during the first three growing seasons; and (3) no litter applied or broadcast application of pine litter to form a 10 to 15 cm layer in the first growing season. Through 12 growing seasons, the fertilization or herbicide treatment significantly increased stand growth (α = 0.05), and these two treatments had an additive effect (no treatments, 209 m3/ha; fertilization, 328 m3/ha; herbicide, 280 m3/ha; fertilization and herbicide, 362 m3/ha). However, because litter application probably had a minor fertilization effect, the fertilizer and litter combination produced the greatest yield (370 m3/ha). The herbicide and litter combination adversely affected pine survival, and so applying all three treatments was no more effective than fertilization alone. The loblolly pine overstory was the dominant factor influencing the long-term development of the understory.

Fuel manipulation with herbicide treatments to reduce fire hazard in young pine (Pinus elliottii × P. caribaea) plantations in south-east Queensland, Australia

“…Haywood et al 2003;Jylhä and Hytönen 2006). Observations in the weeks following herbicide application in the current study indicated some pine-needle necrosis on lower branches.…”

Above- and below-ground biomass accumulation, production, and distribution of sweetgum and loblolly pine grown with irrigation and fertilization

“…Stem production in our study compared favorably with other intensively managed loblolly pine studies of similar age in the southeastern United States (Table 7). Increased fertilization rates (Samuelson et al 2004;Allen et al 2005a) or greater stocking levels (Haywood et al 1997;Adegbidi et al 2002Adegbidi et al , 2005Allen et al 2005a) may be reasons why other studies showed greater stem production rates. Production and volume accumulation are expected to continue increasing until intertree competition exceeds a basal area threshold of 25 m2.ha-I .…”

An integrated analysis of 33 Eucalyptus trials linking the onset of competition-induced tree growth suppression with management, physiographic and climatic factors

“…That lowintensity burning has the potential to stimulate the growth of vegetation, particularly some woody species, has been recorded [1,16,23,31]. Conversely, retaining the post-harvest residues as an organic mulch on the site has been shown to reduce the rate of growth of competitive vegetation [4,8,12,16]. Schumann et al [26] demonstrated that post-harvest residues act as a physical and chemical barrier, reducing the rate of seed germination thereby delaying the onset of inter-specific competition.…”