Pedosphere 7(2): 141--148, 1997
ISSN 1002-0160/CN 32-1315/P
©1997 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Responses of nitrogen and related enzyme activities to fertilization in rhizosphere of wheat |
| YUAN Ling1, HUANG Jian-Guo1 and YU Shang-Qi2 |
1 College of Natural Resources and Environment, Southwest Agricultural University, Chongqing 630716 (China)
2 Equipment Division, Southwest Agricultural University, Chongqing 630716 (China) |
| ABSTRACT |
| In the present experiment, wheat seedlings (Trticucum aestivum L.) were grown on a purple soil with various fertilizer treatments in order to investigate the responses of nitrogen and related enzyme activities in the rhizosphere. The results revealed the increments of both organic matter and total N in the soil with the proximity to the growing roots, especially in the treatment of supplying pig manure in combination with chemical fertilizer, suggesting that they could come from root and microorganism exudation which could be intensified by inorganic-organic fertilization, being of benefit to improving the physical and biological environment in the rhizosphere of wheat. Much more inorganic N was observed in the fertilized soils surrounding wheat roots than in the CK treatment, indicating the improvement of crop N supply in the rhizosphere of wheat by fertilization. The activities of invertase, urease and protease in the root zone were greatly enhanced as compared to those in the other parts of soils except that the urease activities were similar in the rhizosphere and nonrhizosphere of the CK and pig manure treatments, indicating that invertase and protease could be produced by growing roots and rhizosphere microorganisms, in contrast to urease which could be stimulated by urea. Also, significant increment of these three enzyme activities in the rhizosphere of wheat by fertilization, especially by application of chemical fertilizer combined with pig manure, suggested that fertilization not only accelerated the renewal of organic matter but also enhanced bioavailability of organic N in that soil zone. This could be the reason why the total amount of inorganic N available for plants was increased more obviously in the rhizosphere of wheat of the fertilization treatments than in that of the CK treatment. |
| Key Words: nitrogen, rhizosphere, soil enzyme, wheat |
| Citation: Yuan, L., Huang, J. G. and Yu, S. Q. 1997. Responses of nitrogen and related enzyme activities to fertilization in rhizosphere of wheat. Pedosphere. 7(2): 141-148. |
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