ARS | Publication request: Agroforestry planting design affects loblolly pine growth

Submitted to: Southern Silvicultural Research Conference
Publication Type: Abstract Only
Publication Acceptance Date: May 29, 2008
Publication Date: N/A

Technical Abstract: The effect of plantation design on resource utilization has not been adequately investigated in agroforestry plantations. An experiment was conducted near Booneville, AR on a silt loam soil with a fragipan. Loblolly pine trees were planted in 1994 in an east-west row orientation in three designs: two-rows (1.2 x 2.4 m) with a 7.3 m alley, four rows (1.2 x 2.4 m) with a 12.2 m alley, and a rectangular 1.2 x 2.4 m configuration. Each 0.4 ha design was replicated three times, and had 1540 tph (two- and four-row designs), and 3,340 tph (rectangular design) at planting. An estimated 75 to 90% of trees survived to 2007. Height and dbh were measured for six years (2002-2007) in 0.047 ha plots. Tree height increased annually from 7.30 m (2002) to 13.27 m (2007), and designs did not differ in height within years. There was a year x design interaction effect for dbh. For any given year, dbh was greatest in the two-row design; the four-row design had greater dbh than the rectangular design in 2004-2007. Row location (north, south, or middle rows depending on the design) did not have an effect on dbh in two-row and rectangular designs, but exterior rows in the four-row design had greater dbh than interior rows. Overstocking constrained dbh growth in the rectangular design, but this design could have value for pine straw production. The two- and four-row designs could be used for silvopasture.