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

ABSTRACT

This 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

KEYWORDS:

• Panax notoginseng
• cadmium
• nitrogen
• potassium
• bioavailable
• saponins

Highlights

1. Cd accumulation decreased the content of PNS in the main roots of P. notoginseng

2. Formula fertilization of N and K can reduce the Cd accumulation in P. notoginseng

3. Formula fertilization of N and K promotes the PNS accumulation under Cd stress

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Natural Science Foundation of China [No. 81460580]; China Postdoctoral Science Foundation [No. 167358]; Standardization of Traditional Chinese Medicine Project [ZYBZH-C-YN-58]; Ministry of Science and Technology of Yunnan Province, China [No. 2016ZF001, No.2017ZF014].