Absorption and Distribution of Nitrogen,Phosphorus and Potassium in Scutellaria baicalensisGeorgi and Their Relationships to Dry Matter Accumulation

To study the relationship between the accumulation of dry matter and the absorption characteristics of N,P and K in Scutellaria baicalensis Georgi.Field experiments and sampling analysis were used to study the accumulation capacity of dry matter and N,P and K at different growing stages of S.baicalensis Georgi.The accumulation of dry matter in S.baicalensis Georgi increased with growth,and reached 61.62% of the total accumulation within 52-85 d after germinating.During the whole growth period,the accumulation capacity of potassium was the highest,followed by nitrogen,with phosphorus the lowest.The accumulation ratio of N,P and K was 2.8 ∶1.0 ∶2.9,and they were all found in higher concentrations in the roots than aboveground parts.The accumulation of N,P and K in the root showed an increasing-decreasing-increasing trend with different growing stages.These results showed that dry matter accumulation and nitrogen,phosphorus and potassium accumulation were correlated positively.To produce 100 kg root,S.baicalensis Georgi needed to absorb 6.34 kg of N,2.60 kg of P2O5,7.02 kg of K2O from the soil and fertilizer.