Predominant sandy, Beach Ridges Interspersed with Swales (BRIS) soil is a problematical soil for agriculture. It requires structure and capacity improvement due to its weak composition, low water retention capacity and high leaching of nutrients. However, there are hopes to improve it using different fertilizers in combination with organic matter. Phosphogypsum organic (PG organic) is an agricultural soil conditioner formulated from industrial by-products and organic filler material. This research was carried out to investigate the accumulated levels of heavy metals and radionuclides in water, soil and plants between BRIS soil under PG organic conditioner treatment and normal BRIS soil.
The result revealed that the PG organic’s particles are as similar to the reported pattern for calcium sulfate hydrate through powder X-ray diffraction (XRD). The heavy metals measured in the surface and borehole water, and soils were below the target values for raw drinking water and in the Dutch list, respectively. The values for biological accumulation coefficients, contamination factors, I-geo index and pollution load index (PLI) showed that there was no accumulation of metals in grain, no contamination and no pollution in the BRIS soil that received from the PG organic. Natural radioactivity concentrations, 226Ra (238U series), 228Ra (232Th series), and 40K in the collected samples were also measured. Naturally occurring radionuclide concentrations, such as 226Ra, 228Ra, and 40K, in soil and plant tissue were found to be lower than the average value reported by several earlier studies in Malaysia. There was no leaching of natural occurring radionuclides to the groundwater, nor was there discharge to the nearest river. The calculated radium equivalent (Raeq) in soil for this study was lower than the recommended value of 370 Bq/kg soil.
Therefore, the application of PG organic to the studied soil had no impact on the soil, plants and water and suitable as a soil conditioner in BRIS soil.