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

摘要： 为了探讨菘蓝干物质累积和氮、磷、钾吸收与分配的特点，通过田间小区试验和采样分析，研究了菘蓝不同生育期植株的干物质和氮、磷、钾累积量。结果表明，菘蓝干物质的累积量随生长进程不断增加，呈“S”曲线型；近60%干物质累积在菘蓝生长60 d时形成；在120～150 d，菘蓝出现第二个生长高峰期，干物质占总累积量的 31.72%；一年生菘蓝只进行营养生长，物质积累与分配只在叶与根这两个器官间进行，并且干物质分配主要以叶部为主，其分配率占50%以上。在整个生育期，菘蓝对N的吸收累积量最大，K2O次之，P2O5最小，N、P2O5、K2 O吸收比例约为7.78∶1∶3.20，并且随着菘蓝生长期的延长，叶部氮磷累积总量及分配比例均在不断增加；而对于菘蓝根部来说，虽然氮磷累积总量在不断增加，但是所占总累积量比例却有所降低；钾在叶、根部累积及分配规律则与氮磷相反。

关键词: 菘蓝, 干物质, 氮, 磷, 钾