รายละเอียดเอกสาร

Chemical fertilizers have been extensively used in Sri Lanka, and they have contributed to the pollution of groundwater and soil. Therefore, a field experiment was conducted to reduce the potential risk of toxic metal contamination of rice farming through sustainable nutrient management, with the scope of replacing the conventional chemical fertilizers. The field experiment comprised the addition of organic amendments, consortium of biofertilizers, and chemical fertilizers. Two improved rice varieties and three traditional rice varieties were grown. The plant-available and total Cd, As, Pb, and Hg in soil, rice roots, and grains in each system were analyzed. The results revealed that organic soil management is an effective soil remediation technique for rice soil to neutralize the toxic heavy metals (e.g. Pb, Hg, Cd) and metalloids (As) and lead to a harvest with minimum heavy metal contamination (p < 0.05). Natural soil amendments such as compost, biochar, and biofertilizers, which reduce the heavy metal concentrations of soil and rice grains, could be recommended for soil application, instead of chemical fertilizers, for both the traditional and the improved rice varieties.