施用氯化钾对马铃薯氯含量的影响及动态氯临界值研究OA北大核心CSTPCD

[Objectives]By studying the effects of potassium chloride(KCl)application rate and timing on chloride nutrient characteristics and yield in potato,the chlorine-sensitive period and indicator organs,based on potato tuber yield,were identified.Additionally,the dynamic Cl-critical value of the indicator organs during the chlorine-sensitive period was determined,providing a reference for the safe application of chloride-containing fertilizers,such as potassium chloride,in potato production.[Methods]Field experiments were conducted using the variety'Youjin'.Under consistent conditions of K2O application rate and timing,different proportions of KCl were applied as base and top dressing.Plant samples were collected at key growth stages to determine the Cl-content and biomass of each organ,and tuber yield and yield component factors were measured at maturity.The correlation between Cl-content in different organs and yield was analyzed to determine the indicator organ and sensitive period for Cl-in potatoes,as well as the threshold Cl-content in the indicator organ during the sensitive period.[Results]The application rate and timing of KCl significantly increased the Cl-content and Cl-accumulation in different organs of potatoes(P<0.05),but the Cl-content in tubers(0.1%-0.6%)remained significantly lower than in vines(0.4%-4.1%)(P<0.05).The highest accumulation of Cl-in vines reached 45.0 kg/hm2,with the distribution ratio reduced to about 45%at the mature stage.Cl-accumulation in tubers reached 31.73 kg/hm2 at the mature stage,with the distribution ratio reaching about 55%.The Cl-accumulation rate in vines peaked during the tuber formation stage,averaging 1.43 kg/(hm2·d),while the Cl-accumulation rate in tubers peaked at the mature stage,averaging 0.85 kg/(hm2·d).The Cl-content in leaves during the seedling and tuber formation stages was significantly negatively correlated with tuber yield(P<0.05).When the Cl-content in leaves was below 0.7%during both stages,relative tuber yield was≥100%.However,when the Cl-content in leaves exceeded 1.5%during the seedling stage and 2.1%during the tuber formation stage,the relative tuber yield dropped below 95%(P<0.05).Therefore,leaf Cl-content during the seedling and tuber formation stages can be used as an indicator for potato tuber yield.[Conclusions]Based on potato yield,leaf Cl-content can serve as an indicator of the chlorine nutritional status of potatoes.The Cl-critical value during the seedling stage is 1.5%,while the Cl-critical value during the tuber formation stage is 2.1%.