摘要
[Objective] The paper was to study the effects of nitrogen deposition on enzyme activity in different layers of soil. [Method] With grass-land located in Zhuqudeng Village, Bujiu Township, Linzhi City, the Tibet Autonomous Region, as the object, nitrogen deposition was simulated from July 2014 to August 2015. Four N addition treatments were established: control (0 kg·hm^2/a), low N (LN, 25kg·hm^2/a), medium N (MN, 50 kg·hm^2/a) and High N (HN, 150 kg·hm^2/a), aiming at measuring enzyme activity (invertase, catalase, urease, amylase, cellulase, polyphenol oxidase and β-glucosi- dase) in different layers of grassland soil (0 -20 cm and 20-40 cm). [Result] (1) Different levels of simulated nitrogen deposition had significant impact on invertase and β-glucosidase at the soil depth of 0-20 cm (P〈0.05), but no significant impact on catalase, urease, amylase, cellulase and polyphenol oxidase(P〉0.05); invertase, polyphenol oxidase and β-glucosidase had significant response to nitrogen deposition at the soil depth of 20- 40 cm (P〈0.05), while catalase, urease, amylase and cellulose had no significant response (P〉0.05). (2) The activities of invertase and polyphenol oxidase were enhanced at the soil depth of 0-20 cm, and that of β-glucosidase was inhibited. (3) With the deepening of nitrogen deposition, the ac- tivities of invertase and cellulose were enhanced at the soil depth of 20-40 cm; the activity of polyphenol oxidase was reduced in LN treatment, but increased in HN treatment; the activity of β-glucosidase was increased in LN treatment, but decreased in MN treatment. (4) With the deepening of soil layers, invertase and polyphenol oxidase responded similarly to simulated nitrogen deposition. [Conclusion] The results provide certain scientific basis and fundamental data for better understanding and evaluating the effects of nitrogen deposition on enzyme activity in grassland soil.
[Objective] The paper was to study the effects of nitrogen deposition on enzyme activity in different layers of soil. [Method] With grass-land located in Zhuqudeng Village, Bujiu Township, Linzhi City, the Tibet Autonomous Region, as the object, nitrogen deposition was simulated from July 2014 to August 2015. Four N addition treatments were established: control (0 kg·hm^2/a), low N (LN, 25kg·hm^2/a), medium N (MN, 50 kg·hm^2/a) and High N (HN, 150 kg·hm^2/a), aiming at measuring enzyme activity (invertase, catalase, urease, amylase, cellulase, polyphenol oxidase and β-glucosi- dase) in different layers of grassland soil (0 -20 cm and 20-40 cm). [Result] (1) Different levels of simulated nitrogen deposition had significant impact on invertase and β-glucosidase at the soil depth of 0-20 cm (P〈0.05), but no significant impact on catalase, urease, amylase, cellulase and polyphenol oxidase(P〉0.05); invertase, polyphenol oxidase and β-glucosidase had significant response to nitrogen deposition at the soil depth of 20- 40 cm (P〈0.05), while catalase, urease, amylase and cellulose had no significant response (P〉0.05). (2) The activities of invertase and polyphenol oxidase were enhanced at the soil depth of 0-20 cm, and that of β-glucosidase was inhibited. (3) With the deepening of nitrogen deposition, the ac- tivities of invertase and cellulose were enhanced at the soil depth of 20-40 cm; the activity of polyphenol oxidase was reduced in LN treatment, but increased in HN treatment; the activity of β-glucosidase was increased in LN treatment, but decreased in MN treatment. (4) With the deepening of soil layers, invertase and polyphenol oxidase responded similarly to simulated nitrogen deposition. [Conclusion] The results provide certain scientific basis and fundamental data for better understanding and evaluating the effects of nitrogen deposition on enzyme activity in grassland soil.
基金
Supported by National Natural Science Foundation of China(31360119,31460112)
Innovative Ex-perimental Project for College Students of Tibet Agriculture&Animal Husbandry University(2015)
Pilot Project of Forest Education and Training Plan for Outstanding Talents in Agriculture and Forestry(2016)