Welcome to visit Scientia Silvae Sinicae，Today is

Scientia Silvae Sinicae ›› 2015, Vol. 51 ›› Issue (7): 21-27.doi: 10.11707/j.1001-7488.20150703

Previous Articles     Next Articles

Effects of Sub-Irrigation Gradients on Growth and Nutrient Status of Containerized Seedlings of Quercus variabilis

Chen Chuang, Liu Yong, Li Guolei, Sun Qiaoyu, Wang Yan, Wan Fangfang   

  1. Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry University Beijing 100083
  • Received:2014-04-09 Revised:2014-10-19 Online:2015-07-25 Published:2015-08-14

PDF (PC)

610

Abstract:

[Objective] This research was carried out to investigate the effects of sub-irrigation gradients on water use efficiency, morphology and nutrient status, and to provide a scientific basis for precision irrigation of containerized Quercus variabilis seedlings. [Method] Annual containerized seedlings of Q. variabilis using two container sizes (D40 container: volume 656 cm3, specification 6.4 cm×25 cm; D60 container: volume 983 cm3, specification 6.4 cm×36 cm) were treated with four sub-irrigation gradients (85%, 75%, 65%, 55% saturated medium weight) to investigate the changes of water consumption, growth, nutrient status and electrical conductivity (EC) of the growing medium.[Result] 1) The water consumption of containerized Q. variabilis seedlings decreased successively when sub-irrigation gradients dropped. The water use efficiency did not show similar patterns, but the higher sub-irrigation gradient had the higher water use efficiency. 2) The seedlings with sub-irrigation of 85% and 75% saturated medium weight reached the maximum values in height, diameter, stem biomass, root biomass and total individual biomass in all treatments, and no significant difference was found between these two sub-irrigation gradients, but higher or significantly higher than other treatments. 3) There was no obvious pattern among different treatments in nutrient concentration. However, the seedlings with sub-irrigation of 85% and 75% saturated medium weight had significantly higher nutrient content in plants or different organs than other treatments, and there was no significant difference between these two treatments in nutrient content. 4) The seedlings with large size containers had water consumption higher than those with small size containers, and displayed a better performance in morphology, biomass and nutrient content, however, no significant difference was found between different container sizes in nutrient concentration. 5) Sub-irrigation significantly increased the EC value of the upper layer of growing media. The EC value of the middle and lower layers of growing media was not significantly different from each other, but significantly lower than that of the upper layer. There was no significant difference among the treatments in the EC value of the upper layer of growing media. The EC value in our study was lower than the threshold EC value which causes harm to seedlings, and would not have harmful effect on seedlings. [Conclusion] The seedlings with sub-irrigation of 85% and 75% saturated medium weight content with D60 container had the highest water consumption and higher water use efficiency. There was no significant between these two treatments in height, diameter, biomass, and contents of nitrogen, phosphorus and potassium, but higher or significantly higher than other treatments. Their EC values in upper layer of growing medium were lower than the threshold EC value which causes harm to seedlings. Therefore, in terms of water saving and growth promotion, the optimal treatment was D60 container with sub-irrigation of 75% saturated medium weight.

Key words: Quercus variabilis, containerized seedlings, sub-irrigation, sub-irrigation gradients

CLC Number: