Relationship between Lotus Root Quality and Geochemical Conditions in the Xinken Lotus Root Producing Area of Guangzhou

Abstract

BACKGROUND Environmental geochemical conditions affect the quality of famous and special agricultural products. Xinken lotus root is the national product of geographical indication. Exploring the relationship between the geological background of the production area and the quality of lotus root is of great significance to the large-scale planting of Xinken lotus root. OBJECTIVES To reveal the correlation between the quality of lotus root and the environmental geochemical characteristics in the producing area. METHODS Sediment, surface water and fresh lotus root in the Xinken area were systematically sampled and analyzed. RESULTS The concentrations of nutrients, i.e., Mn, Zn, Mo, Co, V and Fe, in the sediment of the lotus root pond were high, in the first grade (rich) level. Selenium was mainly in proper amounts and high selenium grade. The concentrations of Cr, Cu, Hg, Ni, Pb and Zn were lower than those of the soil pollution risk threshold of agricultural land. Cu, Zn, Se, B, Hg, Cd, As, Cr(Ⅵ), Pb and Ni in surface water of the lotus pond met the requirement for irrigation water quality. The lotus root was rich in starch, soluble sugar, K, P, Ca, Mg, Fe, Zn and Se, and the contents of heavy metals and crude fiber were low. The average bioaccumulation coefficients of lotus root for different elements ranged from 0.0484 to 65.67. The enrichment ability of P was the strongest and that of Ge was the weakest. There was a significant positive correlation between B and starch in lotus root pond sediment (p ≤ 0.05), between Ca and protein, while a significant negative correlation between As and soluble sugar. The contents of B, Co, Fe, Mg, Mn, V, Ca and Ge in the sediment of the lotus pond were high, which was beneficial to the accumulation of nutrients in lotus root, and thus production of safe and high-quality lotus roots. CONCLUSIONS Importance should be attached to the supplement of organic matter, Ca, N and Ge in the lotus pond during the planting process and more attention to the potential ecological security risks caused by Cd and As.

Keywords

• xinkentown area
• sediment
• surface water
• inductively coupled plasma-mass spectrometry/optical emission spectrometry
• geochemical conditions
• quality of lotus root