Response of a Rice‐Sugarcane Rotation to Calcium Silicate Slag on Everglades Histosols1

Abstract

AbstractRice (Oryza sativa L.) and sugarcane (Saccharum spp.), grown on organic soils of the Everglades, have been shown to respond favorably to the application of Si from calcium silicate slag. Since these crops may be grown in rotation, it is important to know if slag applied to one crop will benefit the second crop. The objective of the study was to determine the response of rice and sugarcane grown on a Terra Ceia muck (Euic, hyperthermic Typic Medisaprist) to calcium silicate slag applied prior to planting rice, and to slag applied before the planting of sugarcane. Five rates of slag were applied for production of a rice crop, after which time the same plots were planted to sugarcane. Other plots received the same rates of slag just prior to planting sugarcane. Slag applications increased both rice straw Si and sugarcane leaf Si concentrations. A single application of slag prior to planting rice increased production of both the rice and sugarcane crops in the rotation. The combined plant and ratoon rice grain yields were significantly increased 50% by slag application. Slag application also increased harvested cane (biomass) yields 23%, and sugar yields by 25%. Somewhat greater sugarcane plant responses were observed from slag applied immediately before planting than from slag applied before the rice and cane rotation treatment. On the average, slag applied at 20 Mg ha−1 before rice increased sugar yield by 16%, compared to a 21% increase when slag was applied before cane.