Improving the management of acid and sodic soils with green trash retention using calcium-based ameliorants/products : SRDC final project report BSS199

Abstract

Although the advantages of leaving cane residues on the harvested land have been well documented, and nutrient cycling in relation to green-cane trash blanketing has been well examined within a Cooperative Research Centre for Sustainable Sugar Production (CRC Sugar) program activity, little work has been done to investigate the effects of trash management on soil chemical properties and the ameliorative advantages of applying Ca-containing amendments to crop residues. As lime, lime/gypsum applications are generally used to ameliorate acid soil conditions, a Ca-source followed by leaching is the principal strategy for managing sodic soils, and mill by-products (mill mud and mill ash) are often applied to plant cane, it was considered pertinent to investigate the effects of these and other amendments on the decomposition of trash on sugar industry soils.This project aimed at quantifying the effects of trash retention on soils acidity, examining the efficacy of Ca-containing amendments and trash for ameliorating sodic soils, assessing the effect of Ca-based amendments on trash decomposition and nutrient availability, and quantifying trash decomposition and C and N relationships. To do this, the project comprised four distinct but interlinked facets and included a series of laboratory investigations, glasshouse experiments and a field trial.