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Chinese Journal of Applied Ecology ›› 2016, Vol. 27 ›› Issue (4): 1046-1052.doi: 10.13287/j.1001-9332.201604.001

• Special Features for 2020 Annual Meeting of Ecological Society of China • Previous Articles     Next Articles

Effects of gel made by super absorbent polymers and urea on fine root growth and nitrogen use efficiency of Platycladus orientalis bareroot seedlings.

JING Da-wei1,2, XING Shang-jun2*, LIU Fang-chun2, MA Hai-lin2, DU Zhen-yu2, MA Bing-yao2, YU Xue-dou1, ZHU Ya-ping1   

  1. 1Dezhou University, Dezhou 253023, Shandong, China;
    2Shandong Forestry Academy, Ji’nan 250014, China
  • Received:2015-05-05 Revised:2015-10-14 Online:2016-04-22 Published:2016-04-22
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (31500513), the Science and Technology Development Plan of Shandong Province (2010GSF10621), the Science and Technology Talent Introduction Project of Dezhou University (311890), the Natural Science Foundation of Shandong Province (ZR2013GL001) and the Soft Science Research Plan of Dezhou City (2013-43).2015-05-05 Received, 2015-10-14 Accepted.*

Abstract: A pot experiment including five treatments, i.e., CK (neither fertilizer nor super absorbent polymers), U (urea alone), S [super absorbent polymers (SAP) alone], SUM (SAP mixed with urea) and SUG (gel made of SAP and urea) was conducted to evaluate their effects on fine root morphological characteristics, fine root absorption area, fine root nitrogen metabolism and nitrogen use efficiency of Platycladus orientalis bareroot seedlings. Results showed that compared with U treatment, the SUG treatment significantly increased the biomass, length, specific root length, surface area and volume of fine root. The total absorption area and active absorption area of fine root were also increased remarkably under the SUG treatment. The specific root length in the SUG treatment was increased by 34.7%, 37.9%, 41.1% and 12.4% compared with the treatments of CK, U, S and SUM, respectively. Compared with the U treatment, the activities of nitrate reductase, glutamine synthase, glutamate synthase and glutamate dehydrogenase in fine root of the SUG treatment was improved by 41.2%, 76.6%, 30.7% and 125.8%, respectively, while the ratio of GS to GDH decreased. Not only the ground diameter and plant height, but also the dry matter accumulation of aboveground and underground parts was remarkably enhanced under the SUG treatment. The nitrogen use efficiency was 40.7% in the SUG treatment, being 118.8% and 44.5% higher than the U and SUM treatments, respectively. Gel made of SAP and urea was able to significantly increase the nitrogen use efficiency, promote the growth and enhance the ability of drought resistance by improving the morphological characteristics, enhancing the absorption area and key enzymes activities of nitrogen metabolism in the fine root of P. orientalis bareroot seedlings.