Contribution of non-exchangeable potassium on soil K availability can be significant, and in such cases, using a soil test that simulates the mechanisms of K release to the soil solution is a research objective. The purpose of the present study was to investigate whether cation resins, which are considered to function as a sink for both solution K and non-exchangeable K released to plants, could reflect accurate relationships with K availability, especially on soils that contain significant amounts of 2:1 clay minerals or for soils under intensive cropping. A greenhouse pot experiment with winter wheat was conducted on soils with different K loadings, and cation resin’s performance in predicting soil available K was tested under different application techniques, in comparison with chemical extraction methods of exchangeable or non-exchangeable K. The study showed that resins buried in soil for a 9-day period predicted more accurately total K uptake by plants ( r 2 = 0.69, p ≤ 0.001), while strong relationships were observed between them and resin-extracted K with the short-term routine extraction procedure ( r 2 = 0.96, p ≤ 0.001). In addition, critical levels of soil K content obtained with the resin burial method at a 9-day adsorption period, as well as for the sum of 3 burial periods (27 days), were estimated at 4.6 and 19.8 mg cm −2 , respectively, indicating that a possible response on K additions would be expected. The study suggests that cation resins could be adopted as a useful tool in explaining K availability of soils within a wide range of K loading, while the resin-burial method applied in field could be combined with laboratory short-term resin routine analysis, building a common comparison base of data obtained.

中文翻译：

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对阳离子交换树脂作为不同钾负荷的希腊北部土壤中钾有效性的土壤测试的初步评估

不可交换钾对土壤钾有效性的贡献可能是显着的，在这种情况下，使用模拟钾释放到土壤溶液的机制的土壤测试是一个研究目标。本研究的目的是研究阳离子树脂（被认为是释放到植物的溶液 K 和不可交换 K 的汇）是否可以反映与 K 有效性的准确关系，尤其是在含有大量钾的土壤上2:1 粘土矿物或用于密集种植的土壤。在不同钾含量的土壤上进行了冬小麦温室盆栽试验，并与可交换或不可交换钾的化学提取方法相比，测试了不同施用技术下阳离子树脂预测土壤有效钾的性能。研究表明，在土壤中埋藏 9 天的树脂可以更准确地预测植物对钾的总吸收量（r 2 = 0.69，p ≤ 0.001），而在短期内观察到它们与树脂提取的钾之间的密切关系常规提取程序（r 2 = 0.96，p ≤ 0.001）。此外，在 9 天吸附期以及 3 个埋藏期（27 天）的总和中，通过树脂埋藏法获得的土壤 K 含量的临界水平分别估计为 4.6 和 19.8 mg cm -2 ，表明对 K 加法的可能反应是预期的。研究表明，阳离子树脂可作为解释在宽钾负载范围内土壤的钾有效性的有用工具，而在现场应用的树脂埋藏方法可与实验室短期树脂常规分析相结合，