深松条件下春玉米花后衰老过程中根系生物学变化特征

采用PVC管栽方法，研究模拟犁底层和深松处理下春玉米花后衰老过程中根系的生物学变化特征。结果表明，在玉米花后，相同根层节根数均表现为深松处理>模拟犁底层处理。犁底层影响根系在不同深度土壤空间分布，深松处理20～35 cm 土壤深度和36～75 cm 土壤深度玉米根系体积分别比犁底层处理增加176.33%和185.92%；在模拟犁底层处理下，90%以上的根系主要集中在0～20 cm土壤深度，深松处理90%以上的根系主要集中分布在0～35 cm深度土壤。深松增加下层土壤（30～75 cm）根系比重，根系空间分布更加合理。根系衰老进程，花后20 d开始犁底层处理下36～75 cm土壤深度玉米根系衰老速度加快，该深度根系重量开花期比深松处理低2.91%，花后50 d比深松处理低12.31%。犁底层的存在限制玉米根系的发育，深松有利于增加深层土壤的根系分布，能减缓后期根系衰老速度。

Changes of Root Biologic Properties During Senescence after Anthesis of Spring Maize under Subsoiling Treatment

A pot experiment by PVC tube was conducted to research on root biologic properties during senescence after anthesis of spring maize, with the conditions of simulation plowpan and subsoiling. The result showed that the plowman inhibited the root growth and development, root number with subsoiling treatment was larger than plowpan treatment at the same soil depth layer and the same time. Plowman influenced root spatial distribution of different soil depth, there had a significant difference between two treatments, more than 90 percent of number root were concentrated in the 0-20 cm depth soil layer under the treatment of plowpan, but more than 90 percent number root concentrated in the 0-35 cm depth soil layer, compared to subsoiling treatment; The volume of root under subsoiling treatment increased by 176.33% and 185.92% in 20-35 cm layer and 20-75 cm layer, respectively. The root senescence in 30-75 cm soil depth layer was accelerated under plowpan treatment from 20th day after flowing, compared to subsoiling. And dry weight gap between two treatment were 2.91% reached higher to 12.31% from flowering to 50th day after flowering in 30-75 cm soil depth layer, respectively. Consequently, it can indicate that, the existence of plow pan had limited the maize root growth and development, while the subsoiling treatment not only could distribution of roots to deep soil, but also could postpone root senescence.