Effects of precipitated calcium carbonate from sugar purification on crusting soils

Abstract

Precipitated calcium carbonate (PCC), a by-product of the sugar industry, results from a sucrose juice purification technique. This material has several properties that distinguish it from geological calcite. These properties include an organic load, high water-holding capacity, small particle size, high surface area, and uniformity. A large stockpile of PCC is located at the Holly Sugar refinery in Sidney, Montana. This study was initiated at the request of Holly Sugar to investigate potential PCC application as a soil amendment to local agricultural soils that exhibit surface crusting. Soil surface crusts, initiated by precipitation events, are common in Eastern Montana. These crusts can significantly inhibit crop seedling emergence. This study was designed to evaluate the potential of PCC to ameliorate crust formation in eastern Montana agricultural soils. Bulk soil samples from four different sites and stockpile PCC samples were collected for evaluation. Amendment (PCC) and the four soils were then physically and chemically characterized. Soil crust formation and strength of amended and control soils were evaluated in the laboratory and greenhouse by inducing crust formation and then measuring and analyzing specific soil crust properties and parameters. Soil areal extensibilities from saturated to dry moisture conditions were measured and evaluated. Outdoor trials evaluated seedling emergence success and surface crust strength. Greenhouse trials evaluated seedling emergence and the areal extent of soil surface fractures by a photographic quantification technique. The addition of PCC, at the rates tested, did not ameliorate the problematic physical characteristic of the soils. Soil crusting was not reduced by the amendments used in this study.