Abstract:

This research investigated Angelica sinensis production systems with the objective of identifying opportunities for yield increase and improved mulching practice for management of the soil water and soil thermal environment， and to provide direction for further detailed study of technology and its application in A. sinensis production. The experiment included three planting systems： Hole seeding under ridging with plastic-film mulching （LS）， trenching and slant planting under film-side cultivation （MC） and trenching and slant planting in open field （LD） and studied vertical soil moisture and temperature profiles and root development in each case. It was found that in the leaf development growth stage film mulching increased soil water content in the 0-20 cm soil horizon， compared with LD， by 22.94% in LS and 14.57% in MD （P<0.05）. However， due to rainfall， there was no significant difference in soil water content among different treatments in later growth stages. Mulching also significantly increased the average daily temperature in the 0-15 cm soil horizon， with LS and MC resulting in mean increases of 1.04 and 0.61 ℃， respectively， compared with LD. During the growth period， the daily variation in soil temperature had a sinusoidal pattern with the amplitude of the diurnal variation decreasing with increasing soil depth and the maxima and minima delayed by 1 h for every 5 cm increase in soil depth. Mulching also alleviated the temperature drop overnight and reduced the temperature difference between day and night. When soil temperatures in the 0-15 cm horizon were greater than 14 ℃， the root growth of A. sinensis in the mulching treatments was rapid， and the fresh weight of single roots was significantly higher than that of LD mode. The stem diameter and single root fresh weight were therefore significantly increased in film mulching treatments compared with LD treatment， but there was no significant difference in root length. The soil water content of 0-20 cm horizon was significantly positively correlated with the root length， stem diameter and fresh weight of single roots， which played a homogenizing role in the composition of crude drug yield. In conclusion， film mulching resulted in obvious retention of soil moisture and temperature increase and thus an improved growth environment in the root zone of A. sinensis. Mulching alleviated the slow growth of A. sinensis caused by low temperature and water deficit in spring and would also alleviate water deficit later in the season. Mulching can be recommended as a cultivation system for A. sinensis production in cold and humid areas.

Key words: Angelica sinensis, film mulching cultivation, soil water, soil temperature, root growth