摘要：(N4) in 2015 and 2016. Results showed these cultivars had greater root traits and higher grain yield under N3. Total root number (TRN) and total root length (TRL) of these cultivars reached maximum at 55 days after transplanting (DAT). The new released cultivars YLY900 and S1000 were featured with an improved root system among these cultivars. The percentage of root number on 10-20 cm soil was over 50% compared with other soil layer. A significant positive correlation was found between grain yield and both TRN and TRL at 10-20 cm soil layer (P < 0.01). Given this situation, the grain yield of super rice cultivars could be further improved by increasing the proportion of roots at 10-20 cm soil layer under suitable nitrogen management.
