Formula fertilization of nitrogen and potassium fertilizers reduces cadmium accumulation in Panax notoginseng

Yue Shia, Rongfeng Pua*, Lanping Guob, Jinhui Mana, Bingpeng Shanga, Xiaohong Oua, Chunyan Daia, Pengfei Liua, Xiuming Cuia# & Yang Ye*a#a Yunnan Provincial Key Laboratory of Panax notoginseng, Key Laboratory of Panax notoginseng Resources Sustainable Development and Utilization of State Administration of Traditional Chinese Medicine, Kunming Key Laboratory of Sustainable Development and Utilization of Famous-Region Drug, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, Chinab China Academy of Chinese Medicinal Sciences, Chinese Medica Resources Center, Beijing, ChinaCONTACT Yang Ye yangyekm@163.com; Xiuming Cui Yunnan Provincial Key Laboratory of Panax notoginseng, Key Laboratory of Panax notoginseng Resources Sustainable Development and Utilization of State Administration of Traditional Chinese Medicine, Kunming Key Laboratory of Sustainable Development and Utilization of Famous-Region Drug, Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China* Yue Shi and Rongfeng Pu are co-first authors# Ye Yang and Xiuming Cui are co-corresponding authorsABSTRACTThis study investigated the effect of nitrogen (N) and potassium (K) formula fertilization on cadmium (Cd) accumulation in P. notoginseng. Field investigations as well as formulated N and K fertilizers application experiments were conducted. Field investigations showed that Cd accumulation decreased PNS content in the main roots of P. notoginseng, while PNS content was promoted by soil available potassium (AK) and K in the main roots. The Cd content in P. notoginseng and the bioavailable Cd content in the soil decreased with the increasing of total K (TK) and AK in the soil. The increase of soil pH, total organic matter (TOM) and cation exchange capacity (CEC) values can reduce the bioavailable Cd content in soil, thus reducing the Cd accumulation in P. notoginseng. Under current fertilization in P. notoginseng cultivation, decreased N fertilization can alleviate the deterioration of soil physical and chemical properties. Under identical N fertilization, increasing K fertilization promoted the PNS accumulation (0.3–38.3%), also improved soil physical and chemical properties. Formulated N and K fertilizers application (1:2) experiments showed that reducing application of N and increasing K fertilization could reduce the bioavailable Cd content in soil, and the Cd content also decreased by 0.5–69.6% in P. notoginseng.Abbreviation: PNS: P. notoginseng saponins; F(EXC): Exchangeable fraction; F(Carb): Bound to carbonates fraction; F(Fe-MnOX): Bound to iron and manganese oxides fraction; F(OM): Bound to organic matter fraction; F(RES): Residual fraction; AK: Available potassium; TK: Total potassium; CEC: Cation exchange capacity; TOM: Total organic matter