Effects of fertilizers and pesticides on the mineral elements used for the geographical origin traceability of rice

The application of fertilizers and pesticides significantly affects the contents of some mineral elements in rice. Excluding these mineral elements can improve the accuracy of traceability models of rice. With Longjing 31 (a rice variety) as the study object, we carried out field experiments with different dosage levels of fertilizers and pesticides in Jansanjiang, China. The mineral elements in rice were determined by inductively coupled plasma mass spectrometry (ICP-MS). The effects of different dosage levels of fertilizers and pesticides on the mineral elements in rice were compared through single factor analysis of variance. The elements significantly influenced by fertilizers were Fe, Co, Ni, Se, Rh, Eu, Pr, Tl and Pt. The elements significantly affected by pesticides were Al, Co, and Ni. These elements should be excluded in geographical origin tracing. The predictions of the geographic origin made by Fisher discrimination after excluding the above elements gave an overall correct classification rate of 98.9% and a cross-validation rate of 97.8%. Therefore, it is necessary to exclude mineral elements significantly affected by fertilizers and pesticides in the geographical origin traceability of rice.