不同种植年限菜场叶菜田恶性杂草马齿苋土壤种子库的研究

采用恒温保湿培养法分别对种植1年、6年、8年和10年的菜场叶菜田马齿苋土壤种子库进行了研究。结果表明：随着菜场种植年限的增加，马齿苋土壤种子库种子密度不断升高，与不同年限菜场田间马齿苋种群发生量的调查结果一致。对马齿苋土壤种子库0~20 cm土层的垂直分布进行研究，结果显示，马齿苋土壤种子库的种子密度随着土壤垂直深度的增加呈现逐渐减少的趋势，其中马齿苋种子在0~15 cm范围分布最多，种子密度占整个分布层的90.8%以上；15~20 cm土层的马齿苋种子数量较少，低于9.2%。对上述不同种植年限菜场叶菜田马齿苋土壤种子库的年动态变化研究结果表明，3月和12月马齿苋土壤种子库种子密度较高，6月和9月相对较低，与马齿苋田间发生量的年动态变化相反。

Studies on the Soil Seed-bank of Portulaca oleracea, a Vicious Weed Species in Leafy Vegetable Field ofthe Vegetable Farms with Different Cropping Duration

The objective of the study was to investigate the soil seed-bank ofPortulaca oleracea in 0-20 cm soil layer,which collected from leafy vegetable fields in those farms with different cropping duration.The results showed that thePortulaca oleracea seed density of soil seed-bank enhanced with increased cropping duration.These results obtained from the laboratory were agreed with the real fact in the field.ThePortulaca oleracea seed density of seed-bank gradually reduced along with the soil vertical depth incre...