关键词: 菘蓝, 干物质, 氮, 磷, 钾

Abstract: To study the relationship between the accumulation of dry matter and the absorption characteristics of N, P and K in Isatis indigotica, 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 Isatis indigotica. Results showed that the accumulation of dry matter in Isatis indigotica increased with growth as “S” curve type, and reached 60% of the total accumulation within 60 d after germinating．In 120~150 d, it appeared the second growth peak, accounting for 31.72% of the total cumulative amount of dry matter. For annual Isatis indigotica, only nutrition part growed, so material accumulation and distribution were in the leaf and root only,  and the dry matter distribution rate was  50% more than in leaf. During the whole growth period, the biggest accumulation amount absorption of Isatis indigotica was N, and then K2O, P2O5. Absorption ratio of N, P2O5, K2O was about 7.78∶1∶3.20, and with the extension of Isatis indigotica growth period, the total nitrogen and phosphorus accumulation and allocation proportion in leaf  increased. For Isatis indigotica root, although the total nitrogen and phosphorus accumulation  increased contionually, but the proportion of total cumulative amount decreased. Potassium in leaves and roots of accumulation and distribution rule was contrary to nitrogen and phosphorus.

Key words: Isatis indigotica Fort., dry matter, nitrogen, phosphorus, kalium