Response of Amorpha fruticosa seedlings to drought and rewatering in arid and semi-arid environment

摘要

Amorpha fruticosa is widely planted in arid and semi-arid areas of northern China as the pioneer species for vegetation restoration. To determine the response of A. fruticosa to drought and rewatering, a greenhouse experiment was conducted maintaining desired soil water content following weighing method. Results showed that compensation effects occurred at different growth stages of A. fruticosa after rewatering, when the soil relative water content was ≥70%. Post-drought rewatering significantly triggered the compensatory improvement in plant height (19.49% and 7.23%), basal diameter (49.81% and 9.09%), leaf area (7.82% and 8.16%), root length (1.67% and 0.94%), root volume (10.86% and 11.67%) and dry matter content (26.32% and 12.29%) over control at initial and fast growth stages, respectively,under soil relative water content of 87.84%. Whereas, post-drought rewatering did not significantly affect the recovery of A. fruticosa at late growth stage, but 70% was the ideal soil relative water content for dry matter accumulation as compared to control. Thirty (30) days of drought at initial growth stage and 15 days of drought at fast and late growth stages were relatively ideal for biomass yield. The responses of seedlings to drought stress and rewatering suggest that it could significantly contribute to effective irrigation management of A. fruticosa in arid and semi-arid environment.