Sodium (Na) can alleviate potassium (K) limitations by either increasing K uptake or by substitution of K functions in plants, but there is limited information about the levels of soil Na and K at which these separate Na effects operate in cereals. Barley was grown in two sandy soils to assess plant growth and nutrient uptake responses with varying soil Na (5–95 mg kg⁻¹) and K (30, 90 mg kg⁻¹) treatments. Compared with very low Na (5 mg kg⁻¹), low Na (35, 65 mg kg⁻¹) enhanced barley tillering in low K soil (30 mg kg⁻¹) up to 6 weeks after sowing (WAS). Low K with 95 mg Na kg⁻¹ or adequate K (90 mg kg⁻¹) with 65 mg Na kg⁻¹ also produced more tillers at 6–7 WAS. Shoot dry weight of low K plants was significantly improved by low Na at 7 and 9 WAS and even by 95 mg Na kg⁻¹ at 9 WAS. While low Na increased shoot K concentration and the K/Na ratio in low K plants, 95 mg Na kg⁻¹ mainly increased shoot Na concentration at 7 and 9 WAS. By comparison, soil Na had less effect on shoot K concentration and dry weight of adequate K plants. Barley growth at low soil K was stimulated by increasing K uptake at low Na (35–65 mg Na kg⁻¹), but mainly by Na substitution of K at 95 mg Na kg⁻¹, i.e. the beneficial effect of Na on response of low K plants was attributed to two distinct mechanisms that operated at different soil Na levels.

钠（Na）可以通过增加钾的吸收或通过取代植物中的K来缓解钾（K）的局限性，但关于谷物中这些单独的Na起作用的土壤Na和K含量的信息有限。大麦生长在两种沙质土壤中，以评估土壤Na（5-95 mg kg ^-1）和K（30，90 mg kg ^-1）处理对植物生长和养分吸收的响应。具有非常低的Na（5毫克公斤相比^-1），低的Na（35，65毫克千克^-1）的低K值土壤增强大麦分蘖（30毫克千克^-1）至多播种6周后（WAS）。含95 mg Na kg ^-1的低K或含65 mg Na kg ^-1的足够的K（90 mg kg ^-1）在6-7 WAS时也产生了更多的分ers。低钾植物在7和9 WAS时的低Na含量甚至在9 WAS时甚至通过95 mg Na kg ^-1都显着改善了低钾植物的茎干重量。低钠会增加低钾植物中的地上部钾浓度和钾/钠比，而95 mg Na kg ^-1主要在7和9 WAS时会增加地上部钠浓度。相比之下，土壤Na对适当的K植株的芽K浓度和干重影响较小。在低钾水平（35–65 mg Na kg ^-1）下增加的钾吸收量可刺激大麦生长，但主要是通过在95 mg Na kg ^-1下用Na替代钾，即Na对NaCl响应的有益作用。低钾植物归因于两种不同的机制，它们在不同的土壤Na水平下起作用。