Study On The Effect Of Potassium Fertilizer On Ginseng Growth

Potassium is one of the three elements required for plant growth;it has many functions,such as activating enzymes,regulating osmotic potential and enhancing plant resistance and plays an important role in plant growth.Potassium fertilizer is one of the most important ways to regulate plant growth and development.Ginseng is a perennial herb of Panax Araliacae,it is a precious medicinal plant resource in China,which belongs to the potassium-favoring plant,but the research on the effect of the rational potassium application on the growth and development of ginseng is relatively weak.Therefore,in this study,with two years ginseng as materials of pot experiment,5 potassium application levels were set up.The effects of potassium fertilizer application on soil nutrients,ginseng nutrient absorption and related physiological indexes were studied.The effect of potassium on ginseng growth was clarified,which provided theoretical guidance for the rational application of potassium fertilizer.The results are as follows:1 Soil nutrient and main enzyme activities of cultivated ginseng were studied,the results show that potassium fertilizer application significantly increased soil readily available potassium,available potassium and slowly available potassium,and had no significant effect on total potassium content.The K2 is basically balanced on the soil potassium input and output.The content of soil alkalytic nitrogen and available phosphorus decreased first and then increased with the increase of potassium application,the lowest is K2 and K1,respectively.The content of Ca,Mg and Al increased with the increase of potassium application.The content of Fe,Mn,Cu and Zn increased first and then increased with the increase of potassium application.The content of Fe,Mn and Zn reached the lowest value at K2,Cu content is lowest at K1 and K2 and the difference is not significant.Potassium fertilizer application can promote the absorption of N,P,Fe,Mn,Cu and Zn,but the absorption of nutrients no longer increases or even decreases when the amount of potassium exceeds a certain amount.The activities of soil urease,acid phosphatase and sucrase were increased by potassium fertilizer application.The activity of soil urease and sucrase were the highest at K2.2 Analysis of the nutrient content of ginseng showed that the content of potassium in the root,stem and leaf of ginseng showed an increasing trend with the increase of potassium application.In the early stage of ginseng growth,potassium was mainly distributed in stems and leaves,and the potassium of K0,K1 and K2 in the later period was distributed to the root,while the relative content of potassium of stem and leaf in K3 and K4 was still higher.The nitrogen content of ginseng with different amount of potassium varies with the growth period,and the relative content of nitrogen is always leaf > root > stem,which is not related to the amount of potassium application.Ginseng phosphorus was mainly distributed in roots and leaves,and K2 was most beneficial to the increase of phosphorus content in ginseng roots and leaves.With the growth of ginseng,the content of magnesium in root and the content of calcium and magnesium in the stem and leaf decreased with the increase of potassium application.Magnesium is mainly distributed in leaves.Calcium is mainly distributed in stems and leaves.Different potassium application does not change this distribution,but with the increase of potassium application,it will accelerate the occurrence of this distribution.3 The results of potassium fertilizer application on the physiological indexes of ginseng showed that the root activity and chlorophyll content of ginseng were significantly different,and stem electrolyte leakage had no significant difference.The root activity of K2 and K3 was higher in the early stage of ginseng growth,the chlorophyll content of K2 and K3 was higher,the decrease of chlorophyll content was smaller.4 With the amount of potassium application was different,K0 was not beneficial to the output of sucrose and other photosynthates from leaves,the sucrose and starch photosynthetic products of K4 accumulated more in the leaves and were not beneficial to the distribution of the roots.The contents of starch and soluble sugar in the root of K2 were both high,K2 was beneficial to the accumulation of photosynthetic products in the roots.K4 and K0 were not beneficial to the increase of ginsenoside content.Potassium application can increase the content of SOD,POD and soluble protein in ginseng,and then improve the resistance of ginseng.In general,under the conditions of this experiment,K2 is the best potassium application,which is beneficial to the growth of ginseng and the rational utilization of potash fertilizer.