施用氯化钾对马铃薯氯含量的影响及动态氯临界值研究

Effects of potassium chloride application on the chlorine content of potato and dynamic chlorine critical values

【目的】通过研究氯化钾(KCl)施用量和施用时期对马铃薯氯营养特征及产量的影响,确定以块茎产量为基础的氯敏感时期和指示器官,以及氯敏感时期指示器官的动态Cl^(−)临界值,为马铃薯生产中氯化钾等含氯肥料的安全施用提供参考。【方法】以‘尤金’为供试品种进行田间试验,在K_(2)O施用时期和施用量相同的条件下,分别在基肥和追肥时施用不同比例的氯化钾,选取马铃薯关键生育期进行植株样品采集,分别测定各器官的Cl^(−)含量和生物量,并在成熟期测定马铃薯块茎产量及其构成因子。根据马铃薯不同生育时期各器官Cl^(−)含量与产量的相关性,确定马铃薯对Cl^(−)的敏感时期和指示器官;根据敏感期指示器官Cl^(−)含量与块茎相对产量,确定以马铃薯产量为评价依据的马铃薯动态Cl^(−)临界值。【结果】不同时期施用不同量的氯化钾均会显著提高马铃薯各器官的Cl^(−)含量与Cl^(−)积累量(P<0.05),且块茎中Cl^(−)含量(0.1%~0.6%)显著低于茎叶(0.4%~4.1%,(P<0.05)。茎叶中Cl^(−)积累量最高可达45.0 kg/hm^(2),分配比例在成熟期降至45%左右;块茎的Cl^(−)积累量在成熟期可达到31.73 kg/hm^(2),分配比例增加到55%左右。茎叶中Cl^(−)积累速率在块茎形成期达到最高值,平均约为1.43 kg/(hm^(2)·d);块茎的Cl^(−)积累速率在成熟期达到最大值,平均约为0.85 kg/(hm^(2)·d)。苗期和块茎形成期叶片Cl^(−)含量与块茎产量呈显著负相关(P<0.05),且两个时期叶片Cl^(−)含量低于0.7%时,块茎相对产量≥100%;叶片Cl^(−)含量苗期高于1.5%时,块茎形成期高于2.1%时,块茎的相对产量将低于95%(P<0.05)。【结论】以马铃薯块茎产量为基础,叶片Cl^(−)含量可作为马铃薯氯营养状况的指示器官,在苗期Cl^(−)临界值为1.5%,块茎形成期的Cl^(−)临界值为2.1%。

【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 K_(2)O 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/hm^(2),with the distribution ratio reduced to about 45%at the mature stage.Cl^(−)accumulation in tubers reached 31.73 kg/hm^(2)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/(hm^(2)·d),while the Cl^(−)accumulation rate in tubers peaked at the mature stage,averaging 0.85 kg/(hm^(2)·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%.