Liming has widespread and significant impacts on soil processes and crop responses. The aim of this study was to describe the relationships between exchangeable cation concentrations in soil and the relative yield of spring barley. The hypothesis was that yield is restricted by the concentration of a single exchangeable cation in the soil. For simplicity, we focused on spring barley which was grown in nine years of a long-term experiment at two sites (Rothamsted and Woburn). Four liming rates were applied and in each year the relative yield (RY) and the concentrations of exchangeable cations were assessed. Liming had highly significant effects on the concentrations of most exchangeable cations, except for Cu and K. There were significant negative relationships (either linear or exponential) between the exchangeable concentrations of Mn, Cd, Cr, Al, Fe, Cu, Co, Zn and Ni in soil and soil pH. The relationships between RY and the concentrations of selected exchangeable cations (Mn, Ca and Al) were described well using log-logistic relationships. For these cations a significant site effect was probably due to fundamental differences in soil properties. At both sites the concentrations of exchangeable soil Al were excessive (> 7.5 mg kg⁻¹) and were most likely responsible for reduced barley yields (where RY ≤ 0.5) with soil acidification. At Rothamsted barley yield was non-limited (where RY ≥ 1) at soil exchangeable Mn concentrations (up to 417 mg kg⁻¹) greater than previously considered toxic, which requires further evaluation of critical Mn concentrations.

石灰对土壤过程和作物反应具有广泛而重大的影响。本研究的目的是描述土壤中可交换阳离子浓度与春大麦相对产量之间的关系。假设是产量受到土壤中单一可交换阳离子浓度的限制。为简单起见，我们专注于春大麦，它是在两个地点（Rothamsted 和 Woburn）经过 9 年的长期实验种植的。应用了四种石灰率，并在每年评估相对产量 (RY) 和可交换阳离子的浓度。石灰对大多数可交换阳离子的浓度有非常显着的影响，除了 Cu 和 K。Mn、Cd、Cr、Al、土壤和土壤 pH 值中的 Fe、Cu、Co、Zn 和 Ni。使用对数逻辑关系很好地描述了 RY 和选定的可交换阳离子（Mn、Ca 和 Al）浓度之间的关系。对于这些阳离子，显着的场地效应可能是由于土壤性质的根本差异。在这两个地点，可交换土壤铝的浓度都过高（> 7.5 mg kg⁻¹ )，并且最有可能是土壤酸化导致大麦产量下降（其中 RY ≤ 0.5）的原因。在 Rothamsted，大麦产量不受限制（其中 RY ≥ 1），土壤可交换 Mn 浓度（高达 417 mg kg ^-1）高于之前认为的毒性，这需要进一步评估临界 Mn 浓度。