半夏干物质积累与氮、磷、钾吸收特点的研究

在田间条件下，研究了一年内半夏二个生长季的干物质积累与氮、磷、钾积累的特点及其相互关系。结果看出，半夏植株在苗期干物质积累较慢，珠芽形成和块茎膨大期积累迅速，生长后期（倒苗期）则又减慢。植株对氮、磷、钾的吸收特点与干物质积累趋势基本一致。不同生长期半夏对氮、磷、钾的吸收量不同。在第一生长季，出苗后生长30 d内对氮、磷、钾的吸收量较少，分别占该生长季吸收量的30.6%，27.7%和27.8%；生长至60 d时吸收量迅速增加，分别占该生长季的43.6%，52.3%和49.0%；60 d以后其吸收量又逐渐减少。半夏第二生长季对氮磷钾的吸收特点与第一生长季的基本一致。表明半夏一年内以对氮的吸收量最多，钾次之，磷最少，氮、磷、钾的吸收比例为1﹕0.63﹕0.87。

Dry matter accumulation of Pinellia ternata and its characteristics of nitrogen,phosphorus and potassium absorption

Pinellia ternata Breit is a Chinese traditional medicinal herb. Because of the various medical effects and growing market demand, planting area of P. ternata is increasing in China. In this paper, the dynamics of the dry matter accumulation, and the N, P, K contents of P. ternata at the crop’s different development stages were studied. Results show that the dry matter accumulation rates of P. ternata are relatively lower in seedlings and late growth stages (sprout tumble periods), and higher in bulbis and tuber expanding stages. The absorption rates of N, P and K have the same dynamic regulation with dry matter accumulation, and the absorptive capacities of N, P and K are different. Both in the first growth season and in the second growth season, the absorptive capacities are relatively lower within 30 growth days, which only account for 30.6%, 27.7% and 27.8% of the season total absorptive capacities of N, P and K, respectively, while the capacities increase rapidly within 60 growth days, account for 43.6%, 52.3% and 49.0%, and the capacities decrease after 60 growth days. In the whole growth year (the two growth seasons), the absorptive capacity of N is highest, and the absorptive capacity of K is higher than that of P.