| 铵态氮及硝态氮配比对香蕉幼苗氮素吸收动力学特征的影响 |
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| 引用本文： | 张超一,樊小林. 铵态氮及硝态氮配比对香蕉幼苗氮素吸收动力学特征的影响[J]. 中国农业科学, 2015, 48(14): 2777-2784. DOI: 10.3864/j.issn.0578-1752.2015.14.009 |
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| 作者姓名： | 张超一 樊小林 |
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| 作者单位： | 华南农业大学资源环境学院/广东高校环境友好型肥料工程技术研究中心，广州 510642 |
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| 基金项目： | “十二五”国家科技支撑计划（2011BAD11B04）、国家现代农业产业技术体系建设专项（nycytx-33-07）、广东高校环境友好型肥料工程技术研究中心建设项目（GCZX-A100） |
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| 摘 要： | 【目的】探究不同铵硝配比条件下香蕉幼苗对铵态氮、硝态氮两种形态氮素的吸收特性以及两种氮源离子相互作用对香蕉氮素吸收动力学特征的影响，筛选最适于香蕉氮素吸收利用的铵硝配比，为香蕉氮素营养高效吸收提供理论依据。【方法】依据养分吸收动力学原理，利用改进的耗竭法研究不同铵硝配比营养液中巴西品种香蕉（Musa AAA Giant Cavendish cv. Brazil）幼苗对铵态氮、硝态氮以及总氮的吸收动力学特征。设7个处理：100%铵态氮（100%A）、90%铵态氮+10%硝态氮（90%A+10%N）、70%铵态氮+30%硝态氮（70%A+30%N）、50%铵态氮+50%硝态氮（50%A+50%N）、30%铵态氮+70%硝态氮（30%A+70%N）、10%铵态氮+90%硝态氮（10%A+90%N）和100%硝态氮（100%N）。每个处理设9个氮浓度梯度：0、0.1、0.2、0.5、1、1.5、2、3、4 mmol·L-1。【结果】不同铵态氮﹕硝态氮配合条件下，香蕉苗吸收铵态氮、硝态氮及总氮的规律均符合Michaelis-Menten酶动力学方程，其动力学方程达到极显著水平。NH4+-N比例在10%-70%时，随着NO3--N比例的增加，可以增加香蕉幼苗对NH4+-N的吸收速率。在NH4+-N比例为70%时，NH4+-N的最大吸收速率（Vmax）最大，为55.56 μmol·g-1·h-1，NH4+-N比例超过70%会降低香蕉幼苗对NH4+-N的吸收速率。香蕉幼苗对NO3--N的吸收速率呈现随营养液NH4+-N比例的增加而显著降低的规律。NH4+-N比例从10%增大到90%时，NO3--N的Vmax降低了2.62倍，增加NH4+-N的比例明显抑制香蕉幼苗对NO3--N的吸收。铵硝配比对香蕉根系与NH4+-N和NO3--N的亲和力影响无明显规律。在铵硝配比为3﹕7时香蕉总氮Vmax达到83.33 μmol·g-1·h-1，明显高于其他处理，最有利于香蕉吸收利用氮素。【结论】NH4+-N比例低于70%时，增加NO3--N比例可以促进香蕉幼苗对NH4+-N的吸收，NH4+-N比例高于70%时，增加NO3--N比例抑制NH4+-N的吸收。增加NH4+-N的比例明显抑制香蕉幼苗对NO3--N的吸收，铵硝配比为3﹕7最有利于香蕉吸收利用氮素。
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| 关 键 词： | 香蕉 铵态氮 硝态氮 氮素吸收 吸收动力学 |
| 收稿时间： | 2014-12-17 |
Dynamic Kinetic Characteristics of Different Ratios of Ammonium and Nitrate Absorbed by Banana Seedlings |
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| ZHANG Chao-yi,FAN Xiao-lin. Dynamic Kinetic Characteristics of Different Ratios of Ammonium and Nitrate Absorbed by Banana Seedlings[J]. Scientia Agricultura Sinica, 2015, 48(14): 2777-2784. DOI: 10.3864/j.issn.0578-1752.2015.14.009 |
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| Authors: | ZHANG Chao-yi FAN Xiao-lin |
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| Affiliation: | College of Natural Resources and Environmental Science, South China Agricultural University/Guangdong Province Research Center of Environmental Friendly Fertilizer Engineering & Technology, Guangzhou 510642 |
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| Abstract: | 【Objective】Ammonium and nitrate and their interaction effect on N absorption by banana seedlings were studied to screen the optimum ratio of ammonium to nitrate for banana growth and efficient utilization of nitrogen. 【Method】 The NH4+-N, NO3--N and total nitrogen kinetics of N uptake by banana seedlings were studied by modified depletion method based on the principle of nutrient absorption kinetics in the solution culture with different ratios of ammonium to nitrate. 【Result】 Michaelis-Menten enzyme kinetic model or equation could be applied to describe the patterns of absorption of NH4+-N, NO3--N and total N by banana seedlings in all the treatments and the co-relationship coefficient r was at a significant level. When the rate of NH4+-N was at 10% and 70%, NH4+-N absorption rate increased with the NO3--N addition gradually. The maximum absorption rate (Vmax) of NH4+-N uptake reached the maximum of 55.56 μmol·g-1·h-1, when the NH4+-N ratio increased to 70%. The NH4+-N absorption rate decreased again when the NH4+-N ratio was more than 70%. However, the rate of nitrate absorption of banana declined with the increase of NH4+-N. When the proportion of NH4+-N increased from 10% to 90%, the Vmax of NO3--N decreased by 2.62 times. Therefore, adding NH4+-N would significantly inhibit the banana seedlings to absorb NO3--N. There was no obvious effect of the ratio of ammonium to nitrate on affinity of banana root to NH4+-N and NO3--N. When ammonium to nitrate ratio was 3﹕7, the total nitrogen absorption rate was 83.33 μmol·g-1·h-1, being the maximum rate and in favor of banana to take up nitrogen. 【Conclusion】 When the proportion of NH4+-N was lower than 70%, increase of NO3--N could enhance the banana seedlings to take up NH4+-N. When the ammonium ratio was more than 70%, increase of NO3--N would inhibit the banana seedlings to take up NH4+-N. Increasing ratio of NH4+-N could significantly inhibit the banana seedlings to absorb NO3--N. The optimum ratio of ammonium to nitrate being favor of nitrogen absorption was 3﹕7. |
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| Keywords: | banana NH4+-N NO3--N nitrogen uptake absorption kinetics |
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