Mulched and Soil-incorporated Sugarcane Greenchop Residue and Compost: Effects on Selected Soil Components, Sugarcane Nutrients, Mexican Rice Borer Injury, and Yield

Authors: Showler, Allan

Submitted to: Environmental Systems Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: Burning of sugarcane fields to remove leaves before harvest can have undesirable effects on soil and air, and in some parts of the world the practice has been discontinued. This study, conducted in the Lower Rio Grande Valley of Texas, examined effects of leaf residue, or “greenchop”, remaining in the field after harvest as a mulch, and as soil-incorporated organic matter, on levels of soil and sugarcane plant nutrients, injury by the Mexican rice borer, and sugarcane yield. Although soil-incorporated organic matter increased many nutrients found in leaf tissue, they were not affected by the treatments. Levels of Mexican rice borer injury to sugarcane stalks during the first season, however, was generally greater in the greenchop and organic matter-augmented treatments than in the nontreated control. In the second growing season, important amino acids for insect growth and development were elevated in the organic matter-augmented treatment, the only treatment associated with heightened Mexican rice borer infestations. Greenchop had no significant effects on soil and the nutrients we measured in sugarcane leaf tissues, but it increased the risk of Mexican rice borer-induced injury.

Technical Abstract: Burning of sugarcane, Saccharum spp., fields to remove leaves before harvest can have deleterious effects on soil and air, and in some parts of the world the practice has been discontinued. This study, conducted in the Lower Rio Grande Valley of Texas, the United States, examined effects of leaf residue, or “greenchop”, remaining in the field after harvest as a mulch, as soil-incorporated organic matter, and sprayed with compost extract then soil incorporated, compared against a nontreated control, and soil-incorporated compost, on levels of soil and selected sugarcane plant nutrients, injury by the Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), and crop yield parameters. Although the compost amended soil had greater concentrations of many nutrients, particularly P, Ca, Mg, and Zn, in leaf tissue, those four elements, sugars, and, during the first growing season, free amino acids, were not affected by any of the treatments. Levels of Mexican rice borer injury to sugarcane stalks during the first season, however, were generally greater in the greenchop and compost treatments than in the control. In the second growing season, free histidine and lysine, both essential for insect growth and development, were elevated in the compost treatment, which was the only treatment associated that year with heightened Mexican rice borer infestations. Greenchop had no statistically significant effects on soil and the measured nutrients in sugarcane leaf tissues, but it increased the risk of elevated Mexican rice borer-induced injury.