Study On The Fertilizer Demand Law Of Platycodon In Different Growth Phases

Platycodon,belonging to angiosperm, dicotyledon,asterales,campanulaceae,is usually used as herb and food.The toot of platycodon is traditional Chinese medicine,with the effectiveness as eliminating phlegm,etc.It also can be used to treat Sore throat,cough,etc.The effective components of platycodon are platycodin. The first place which large-scale planting platycodon in China is chishang of zibo in shandong province lies.Now in chishang there have more than 60000 Chinese acres place to plant platycodon, with exports more than 30000 tons.They have few fertilization in platycodon planting process.So comparing the content of N,P,K,Mg and Ca in different growth phases can provide theoretical basis for rational fertilization in platycodon planting process.The study determine the nitrogen content in roots, stems, leaves of platycodon with Kjeldahl method.The study found that the nitrogen content in stems and leaves of platycodon decreased with the plant's growing.In the total growing the nitrogen content decreased by 17.6% and 23% in stems and leaves.On the contrary,the nitrogen content in roots increased by 33.7%.Higher nitrogen content in stems and leaves can make the plant growing rapidly in the seedling stage.The roots have a lower nitrogen content in the seedling stage.The nitrogen content in roots increased with the end of stems and leaves' growing.The roots continue to accumulate nitrogen in the seeding stage.Deep plowing before transplantation should therefore be applied when sufficient nitrogen base fertilizer to ensure seedling stems and leaves of the platycodon need for nitrogen. Nitrogen fertilizer is also needed by the roots of platycodon in the flowering stage.The phosphorus content in platycodon is determined with the Mo-Sb colorimetry.The study found that the phosphorus content in the roots and stems of platycodon is higher in the seedling and flowering stage.The phosphorus accumulation in leaves is higher in the seedling stage. The phosphorus accumulation in roots is higher in the flowering stage.Therefore, the application of phosphate fertilizer should also be carried out before transplantation and flowering. The content of K,Mg and Ca are determined by atomic absorption spectrometry.The potassium content in roots is increasing by 0.24% in the seeding stage. The potassium content in stems and leaves decreased from 0.53%, 0.60% to 0.42%, 0.51%.The potassium content in stems The flowering period is a period of strong demand for potassium to the stems,with the accumulation amount of 16.0mg DW/plant.Therefore, in the budding period may be appropriate to add platycodon potash.Magnesium accumulation in root squaring stage up to 6.5mg DW/plant.Magnesium accumulation in stem is 3.7mg DW/plant in the seedling with 1.0mg DW/plant in the seeding.Before transplantation can exert enough magnesium fertilizer during the growing Campanulaceae basically meet the demand for magnesium.Flowering and seed accumulation of calcium accounted for all the roots of the cumulative amount of 75.8% calcium.The accumulation of calcium in leaves is 2.8mg DW/plant in the flowering with 1.5mg DW/plant in the seedling.The accumulation of calcium in stem is 11.6mg DW/plant in the flowering.