Cadmium accumulation in different crops and agricultural planting suggestions for Cadmium lightly polluted areas in Luoyang City, Henan Province

Objective The purpose of this paper is to screen the crops with low cadmium accumulation, study the influencing factors of cadmium in crops, and guide the safe utilization of agricultural soil lightly contaminated with cadmium.

Methods Cadmium and other elements in the edible parts of 23 crops and the corresponding root soils from Luoyang City were measured. We studied the reasons of excessive cadmium in soil, enrichment trend of cadmium in different crops and its influencing factors to screenout the crops with low cadmium accumulation by mathema-ticalstatistics and correlation analysiscombined with the information of geology and mineral deposits.

Results 6.98% of root soil samples exceeded the national standard of Cd in crop soil. 0.84% of crop samples exceeded the national standard of Cd in crops. The rates of crop exceeding the national standard in the soil with cadmium slightly exceeding the national standardis low.The average cadmium concentration in the edible parts of various crops is ranked as: peanut>okra>cowpea>mung bean>soybean>black bean> sesame>apeseed>pepper>wheat>garlic>red bean>millet>edamame>bean>corn> sweet potato>cherry>pomegranate>pear>Chinese artichoke>apple>grape. Different speciation of Cd is significantly correlated with the total Cd in root soil. The main influencing factors affecting cadmium concentration in edible parts of crops is soil pH, followed by cadmium concentration in soil and concentrations of other elements such as Se, Mo and Zn.The correlation between Cd concentration in edible parts of different crops and soil Cd content and pH is not consistent. In areas with weak cadmium pollution, apples, pomegranates, Chinese artichoke, pears, sweet potatoes, corn, garlic, grapes, beans and cherries are recommended to be planted.Sesame, rapeseed, millet, wheat and peanuts can be farmed in alkaline soil.Sesame, rapeseed, millet, sweet potato and corn and fruits such as apple, pear, grape and cherry can be safely grown in areas with excessive cadmium in wheat grains.Increasing soil pH can also reduce the adsorption of cadmium by wheat grains.

Conclusions The study of cadmium accumulation trends and its influencing factors of different crops could provide scientific basis for the safe utilization of soil with cadmium slightly exceeding the national standard.