干旱胁迫下钾肥用量对烟田土壤钾素时空变化的影响

Effect of Potassium Application on Spatiotemporal Change of Available Potassium in Tobacco Field Soil under Drought Stress

摘要: 采用防雨控水试验研究了干旱胁迫下不同钾肥用量对烟田土壤有效钾浓度时空变化的影响。结果表明,干旱胁迫下随土层加深,烟田土壤有效钾浓度下降;随钾肥用量增加,烟田土壤有效钾浓度增大。随干旱时间延长,烟株根区0~40cm土层土壤有效钾浓度梯度均明显升高,且随施钾量的增加,升高幅度增大。干旱胁迫下烟田0~40cm土层土壤有效钾浓度梯度(K)随干旱时间变化的数学模型为K=atb,这些模型可用于预测干旱条件下烟田不同土层有效钾浓度梯度的变化。

Abstract: A water-controlled experiment was conducted to study the effect of potassium application on spatiotemporal change of available potassium concentration in tobacco field soil under drought stress.The results showed that under drought stress,the concentration of available potassium decreased with the increase of soil depth,while it raised with the increase of potassium rate.With the prolonging of drought time,the concentration gradient of available potassium in rhizosphere(soil depth of 0-40 cm) increased obviously,and raised with the increase of potassium rate.The mathematic model for the gradient of available potassium concentration(K) in soil of 0-40 cm in depth against the length of drought stress time(t) was K=atb,which could be used to predict the change of concentration gradient of available potassium in tobacco field under drought stress.