Evaluation of the potential effects of soil properties on molybdenum availability in soil and its risk estimation in paddy rice

Molybdenum (Mo) is an essential element critical to biochemical processes in plants and animals. The effects of soil properties on the availability of Mo to rice were investigated. A total of 56 paired samples of topsoil and rice were collected. Relevant parameters in soil and Mo in rice grains were measured, and the results were analyzed using statistical methods. Descriptive statistics for Mo contents in soil and soil properties are presented. Mo adsorption can be predicted using the following soil chemical properties: pH, cation exchange capacity, soil organic carbon (SOC) content, inorganic carbon content, and iron oxide content. This study focused on soil pH, SOC, S, and Na2O because these parameters are the most important factors in controlling the levels of soil Mo in correlation analyses. SOC and available P were the best predictors of Mo availability. Among the soil properties in this study, soil pH is the most important factor restricting the supply of soil available Mo. The dominant factors that directly affected Mo availability were the levels of available P and SOC. Leaching and adsorption of Mo in soils were considered key processes that affected the levels of soil available Mo. Rice grown in the study area may pose potential Mo risks to food safety and human health, especially in rural areas.