J Environ Qual. 2019 Sep;48(5):1517-1523. doi: 10.2134/jeq2019.03.0128.
Iodine (I) is an essential trace element commonly deficient in agricultural systems. Whereas there is much information on I in food crops, there is a lacuna of knowledge on the environmental factors that affect pasture I concentrations. We aimed to identify the most important environmental factors affecting the concentration of I in New Zealand pastures, and the consequences to agricultural systems. Soil and pastoral samples were collected throughout the country and analyzed for I and other elements. The soils contained 1.1 to 86 mg I kg, with 0.005 to 1.4 mg kg in the pasture. In 26% of pastures, I concentrations were insufficient for sheep nutrition, whereas 87% contained insufficient I for cattle nutrition. Pasture I concentrations were negatively correlated with the distance from the sea, and the concentration of oxalate-extractable amorphous Al, Fe, and Si oxides, which immobilize soil I. Soil organic C and clay increased I retention in soil but did not significantly affect pasture I concentrations. Future work should investigate how soil properties affect pasture I uptake in inland areas.
碘（I）是一种必需的微量元素，在农业系统中通常缺乏。虽然关于食物作物中的碘有很多信息，但对于影响牧场碘浓度的环境因素知之甚少。我们的目的是确定影响新西兰牧场碘浓度的最重要的环境因素，以及对农业系统的影响。在全国范围内采集土壤和牧场样本，并对碘和其他元素进行分析。土壤中的碘含量为 1.1 至 86 毫克/千克，而牧场上的碘含量为 0.005 至 1.4 毫克/千克。在 26%的牧场上，碘浓度不足以满足绵羊的营养需求，而 87%的牧场上碘浓度不足以满足牛的营养需求。牧场碘浓度与距海的距离呈负相关，与草酸盐提取的无定形 Al、Fe 和 Si 氧化物的浓度呈负相关，这些氧化物会固定土壤中的碘。土壤有机 C 和粘土增加了土壤对碘的保持，但对牧场上的碘浓度没有显著影响。未来的研究应该调查土壤特性如何影响内陆地区牧场对碘的吸收。
