Pedosphere 16(4): 512--518, 2006
ISSN 1002-0160/CN 32-1315/P
©2006 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil enzyme activities with greenhouse subsurface irrigation |
ZHANG Yu-Long and WANG Yao-Sheng |
| College of Land and Environmental Sciences, Shenyang Agricultural University, Shenyang 110161 (China). E-mail: ylzsau@163.com |
| ABSTRACT |
| Various environmental conditions determine soil enzyme activities, which are important indicators for changes of soil microbial activity, soil fertility, and land quality. The effect of subsurface irrigation scheduling on activities of three soil enzymes (phosphatase, urease, and catalase) was studied at five depths (0-10, 10-20, 20-30, 30-40, and 40-60 cm) of a tomato greenhouse soil. Irrigation was scheduled when soil water condition reached the maximum allowable depletion (MAD) designed for different treatments (-10, -16, -25, -40, and -63 kPa). Results showed that soil enzyme activities had significant responses to the irrigation scheduling during the period of subsurface irrigation. The neutral phosphatase activity and the catalase activity were found to generally increase with more frequent irrigation (MAD of -10 and -16 kPa). This suggested that a higher level of water content favored an increase in activity of these two enzymes. In contrast, the urease activity decreased under irrigation, with less effect for MAD of -40 and -63 kPa. This implied that relatively wet soil conditions were conducive to retention of urea N, but relatively dry soil conditions could result in increasing loss of urea N. Further, this study revealed that soil enzyme activities could be alternative natural bio-sensors for the effect of irrigation on soil biochemical reactions and could help optimize irrigation management of greenhouse crop production. |
| Key Words: irrigation scheduling, soil enzyme activity, subsurface irrigation, tomato |
| Citation: Zhang, Y. L. and Wang, Y. S. 2006. Soil enzyme activities with greenhouse subsurface irrigation. Pedosphere. 16(4): 512-518. |
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