关键词: 土壤镉污染, 土壤镉污染, 黑麦草, 镉吸收, 转运系数, 富集系数

Abstract: To determine the suitable sowing date for high-yield and high-quality cultivation of Isatis indigotica in Hexi corridor, an experiment of different sowing dates of Isatis indigotica was carried out in Minle of Gansu Province in 2014. The agronomic characters, medical yield, quality of Isatis indigotica at different sowing dates were analyzed. Results showed that with the delay of the sowing date, the seedling date and the whole growing date were shortened, and the bolting rate decreased obviously. The seedling emergence days of sowing on May 22 were shortened by 15 d, compared with that of sowing on April 12. The growth period was shortened by 42 d, and the bolting rate dropped by 30%. With the delay of the sowing date, the germination rate significantly increased. April 12 had the lowest seedling emergence rate [(40.57±0.56)%], and the germination rate was above 95% after sowing on May 2. The yield of Radix isatidis (5000.25 kg/hm2) and the content of (R,S)- epigoitrin [0.083 /-0.0012)%] reached the highest level when the sowing was conducted on April 22, and the yield of Folium isatidis was the highest (2034.37 kg/hm2) when the sowing was on May 2, but the sowing date had no significant effect on medicinal water content, extract and ash content of Radix isatidis. The best sowing date of Isatis indigotica was from late April to early May in Hexi Corridor, early sowing and late sowing were not conducive to increasing the yield and quality of medicinal materials of Isatis indigotica.