Mulched and soil-incorporated sugarcane greenchop residue and compost: effects on selected soil components, sugarcane nutrients, Mexican rice borer injury, and yield

Abstract

AbstractBurning sugarcane, Saccharum spp., fields to remove leaves before harvest is a routine practice in many sugarcane production areas, including the United States. The method is environmentally deleterious and has been discontinued in some parts of the world. Alternatively, excised preharvest leaf residue, or greenchop, is used as mulch. This field study examined the effects of greenchop, applied in several ways to sugarcane soil, on soil fertility, selected sugarcane plant physiochemicals, injury inflicted by the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), and sugarcane yield parameters, compared to plots augmented by soil-incorporated compost and a nontreated control. The compost amended soil had elevated concentrations of many nutrients, and in sugarcane leaves, heightened concentrations of certain sugars and free amino acids. None of the greenchop treatments affected soil and sugarcane leaf nutrients. During the first year of the study, E. loftini injury to sugarcane stalks during the first season, however, was generally greater in the greenchop and compost treatments than in the control. In the second growing season, the compost treatment was the only treatment associated with heightened E. loftini infestations. Relationships between soils augmented with organic amendments and E. loftini injury to sugarcane are discussed in terms of mediation through physiochemical changes induced by the amendments.