Residual Effects of Liquid Digested Sludge on the Quality of Broomsedge in a Pine Plantation

Abstract

Broomsedge (Andropogon virginicus L.) is generally looked upon with some disfavor as a weed but has been utilized for grazing. Liquid digested sludge (LDS) has been tested as a fertilizer on tree plantations where broomsedge comprises a portion of the understory. Broomsedge samples were collected 4 years after treatment of a slash pine (Pinus caribaea More.) plantation with LDS containing 0, 21.6, 40.5, 62.1, 83.7, and 102.6 t/ha of dry solids. Sludge was applied both as a top application and incorporated prior to tree planting. Crude protein (CP) of grass samples was generally increased with an increase in sludge application. In vitro organic matter digestibility (IVOMD) appeared to decrease with increased sludge application under conditions of top application only. The understory at the 0 and 21.6 t/ha-rates of sludge was about 67% broomsedge. At the higher sludge rates, the understory was only 10% broomsedge or less.