Soil water and fertilizer are two main factors affecting tomato yield and quality, and their optimization management is crucial for sustainable production. There are many studies about the response of tomato growth and fruit yield formation to irrigation level and potassium (K) fertilizer, but few studies have been conducted on the responses of irrigation level and controlled release potassium chloride (CRK), not to mention the different irrigation levels and CRK to KCl blending ratios. In this study, two consecutive growing seasons (2020–2021) tomato pot experiments were presented with three irrigation levels (W₁₀₀, W₈₀, and W₆₀) and three blending ratios of CRK to KCl (100%, 80%/20%, 60%/40%) under the condition that the amount of potassium fertilizer was reduced by 40% compared with conventional application rate. The results revealed that under W₈₀ water conditions, 80% CRK mixed with 20% KCl application led to a significant increase in tomato yield by 4.1–11.9% and 4.6–18.9%, K use efficiency by 11.5–34.2% and 6.1–32.3%, fruit vitamin C content by 9.3–25.3% and 5.6–28.3%, fruit soluble sugar content by 10.2–20.0% and 10.2–24.1% in 2020 and 2021, respectively, compared with the other K fertilization treatments. Meanwhile, the water use efficiency and fruit soluble solid content of W₈₀K₈₀ treatment were also maintained at a high level. Molecular analysis shows that the W₈₀K₈₀ treatment had a higher photosynthetic rate, rubisco content, cytokinin content, and osmotic regulation substances content, and lower abscisic acid (ABA), malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) contents. Our results indicated that 80% irrigation level and 80% CRK-20% KCl blending ratio were the optimal water and K supply mode for tomato production in this study. The result provided useful information regarding greenhouse tomato production that would allow the achievement of higher fruit yield, quality and resource use efficiencies, and provided theoretical and technical support for greenhouse tomato irrigation and K fertilizer application technologies.

土壤水分和肥料是影响番茄产量和品质的两个主要因素，其优化管理对于可持续生产至关重要。关于番茄生长和果实产量形成对灌溉水平和钾（K）肥的响应的研究很多，但关于灌溉水平和控释氯化钾（CRK）的响应的研究很少，更不用说不同的灌溉水平和 CRK 与 KCl 混合比例。在这项研究中，连续两个生长季节（2020-2021 年）番茄盆栽试验采用三种灌溉水平（W ₁₀₀、W ₈₀和 W ₆₀)和CRK与KCl三种配比（100%、80%/20%、60%/40%）在钾肥用量比常规施用量减少40%的情况下。结果表明，在 W ₈₀水条件下，80% CRK 与 20% KCl 混合施用导致番茄产量显着增加 4.1-11.9% 和 4.6-18.9%，钾利用率分别提高 11.5-34.2% 和 6.1-32.3 %，与其他施钾处理相比，2020 年和 2021 年水果维生素 C 含量分别增加 9.3-25.3% 和 5.6-28.3%，水果可溶性糖含量分别增加 10.2-20.0% 和 10.2-24.1%。同时，W ₈₀ K ₈₀处理的水分利用效率和果实可溶性固形物含量也保持在较高水平。分子分析表明，W₈₀ K ₈₀处理光合速率、rubisco 含量、细胞分裂素含量和渗透调节物质含量较高，脱落酸（ABA）、丙二醛（MDA）和过氧化氢（H ₂ O ₂）含量较低。我们的结果表明，80%的灌溉水平和80%的CRK-20% KCl混合比例是本研究中番茄生产的最佳供水和钾供应模式。该结果为温室番茄生产提供了有用的信息，可以实现更高的果实产量、质量和资源利用效率，并为温室番茄灌溉和钾肥施用技术提供理论和技术支持。