The dissolution of fertilisers is the initial process that takes place in soils following fertiliser application and influences the fate and effectiveness of fertilisers. Currently, there are only a few methods for studying fertiliser dissolution in soil. These approaches typically do not accurately represent real soil-fertiliser systems and are susceptible to errors, since they are influenced by processes associated with the loss or retention of the trace ions of the fertiliser. Low field NMR or time-domain NMR (¹H-TDNMR) is typically employed for studying ¹H in fluids (or mobile ¹H), however, special pulse sequences enable the selective detection of ¹H in solids. Furthermore, it is possible to filter out undesired signals like ¹H from minerals and from soil organic matter. This allows for the detection and monitoring of ¹H only from protonated fertilisers (e.g., ammonia, (di)-hydrogen phosphates, etc.). The aim of this study is to present an efficient procedure which monitors the dissolution of fertilisers in soils using ¹H-TDNMR. For this, six contrasting New Zealand soils and four protonated fertilisers - NH₄Cl, NH₄NO₃, NaH₂PO₄.H₂O, and (NH₄)₂HPO₄ - were utilised. The proposed method efficiently, accurately, and precisely, monitored the dissolution of the studied fertilisers in all the tested soils under different rain regimes, from violent rain (60 mm h^− 1) to light rain (2 mm h^− 1) with a time interval (temporal resolution) as short as 5 s.

肥料的溶解是施肥后在土壤中发生的初始过程，它会影响肥料的命运和有效性。目前，只有少数几种方法可以研究肥料在土壤中的溶解。这些方法通常不能准确代表真实的土壤肥料系统，并且容易受到错误的影响，因为它们受到与肥料痕量离子损失或保留相关的过程的影响。低场 NMR 或时域 NMR （¹H-TDNMR） 通常用于研究流体中的 ¹H（或移动 ¹H），但是，特殊的脉冲序列能够选择性检测固体中的 ¹H。此外，还可以从矿物质和土壤有机质中过滤掉不需要的信号，如 ¹H。这允许仅从质子化肥料（例如氨、（二）-磷酸氢盐等）中检测和监测 ¹H。本研究的目的是提出一种使用 ¹H-TDNMR 监测肥料在土壤中的溶解的有效程序。为此，使用了六种对比鲜明的新西兰土壤和四种质子化肥料 - NH₄Cl、NH₄NO₃、NaH₂PO₄。使用 H₂O 和 （NH₄）₂HPO₄ - 。所提出的方法高效、准确和精确地监测了在不同降雨条件下研究的肥料在所有测试土壤中的溶解情况，从暴雨 （60 mm ^h-1） 到小雨 （2 mm ^h-1），时间间隔（时间分辨率）短至 5 秒。