两种土壤条件下荒漠盐生植物根际系统养分分布的实验研究

摘要/Abstract

摘要： 采用水平根垫法对四种不同类型的荒漠盐生植物进行栽培实验,应用冰冻薄层切片法对距根表不同距离的土壤进行分层取样,并测定不同层次土壤中pH值、总盐、速效N、有效P、速效K、交换性Ca和Mg的含量。结果表明,在盐土中,距根表不同距离的土壤中,pH值均呈有规律的梯度分布,即根际微区pH值较土体下降,且距根表越近,pH值越低,而在棉田土中却没有显著变化;总盐在根际出现较大的亏缺区。在盐土中,四种植物根际的速效N都呈现出亏缺的趋势,在0—3 mm范围内变化幅度最大。四种植物根际速效N在棉田土壤中的变化趋势与盐土中相似,也呈现出亏缺,但亏缺的程度稍低。四种植物根际有效P的变化与速效N不同,在盐土中,四种植物根际有效P呈现富集的趋势,但富集程度不高,最大富集范围出现在距根表0—5 mm范围内,芦苇的富集率最低。在棉田土中,根际有效P的变化与在盐土中相反,表现为亏缺,并且亏缺幅度很大;四种植物根际速效K的变化与有效P相似。根际交换性Ca的在盐土和棉田土中的分布有差异。在盐土中,根际中交换性Ca分布较均匀,没有显著的变化,而在盐土中却富集。在荒漠盐土中, N、P和K在几乎所有植株中地上部分都显著大于地下部分,N和K尤为显著;除芦苇外,Ca和Mg则是地下部分大于地上部分,琵琶柴尤为显著,这可能与它们各自的生理类型有关。

关键词: 根际, 盐生植物, 荒漠, 养分, 分布, 冰冻切片

Abstract: Study on the distribution of rhizosphere nutrient is an important step in improving our understanding of desert halophytes. Improved understanding will enhance our ability to model nutrient dynamics and on a broader scale to develop effective method to spread desert halophytes. However, only limited attention has been focused on the rhizospheric soil of the halophytes in arid desert region, and still less is known about how rhizosphere nutritional distribution varies among plant species. Under the two soil conditions, four desert halophytes were planted in pots using horizontal root-mat technology. Soil samples were stratified collected by thin slicing the rhizosphere soil along the distance from the root plane of seedlings, and the pH value, available nitrogen(N), phosphorus(P) and potassium(K), exchangeable Ca and Mg contents were determined. The results showed that there existed a special gradient distribution of the pH and the contents of N, P, K, Ca and Mg along the distance from the root plane of the seedlings. The results showed that there existed a special gradient distribution of the pH and the contents of salt ions along the distance from the root plane of the seedlings. The pH decreased in the rhizosphere soil compared with the bulk soil and increased gradually and reached its background value of bulk soil in desert solonchak; there were not significant changes in the rhizosphere soil to cotton crop soil. There was a wide depletion zone of soil available N and exchangeable Mg near the root plane in two soil. The biggest depletion ratio of available N occurred at the site 3 mm from the root plane. For the available P and K,there existed a obvious depletion zone in the rhizosphere of cotton crop soil, but there was a accumulation in the rhizosphere of desert solonchak. Exchangeable Ca does not change significant in the rhizosphere soil to desert solonchak, but it increased in the rhizosphere of cotton crop soil. Available N and P in the aboveground part of the plant were more than underground part, especially for succulent halophytes and salt secrete halophyte.

Key words: rhizosphere, halophyte, desert, nutrient, distribution, frozen slice

中图分类号:

Q945.12

弋良朋;马健;李彦*. 两种土壤条件下荒漠盐生植物根际系统养分分布的实验研究[J]. 中国沙漠, 2008, 28(3): 443-448.

YI Liang-peng;MA Jian;LI Yan. Distribution of Soil Nutrient Concentration in the Rhizosphere System of Desert Halophytes under Two Soil Conditions[J]. JOURNAL OF DESERT RESEARCH, 2008, 28(3): 443-448.

参考文献

[1]Coata C,Dwyer L M,Dwyer M,et al.A sampling method for measurement of large root systems with scanner-based image analysis[J].Agronomy Journal,2000,92:627-627.
[2]Chassot A,Richner W.Root characteristics and phosphorus uptake of maize seedings in a Bilayered soil[J].Agronomy Journal,2002,94:118-127.
[3]Liao H,Ge Z Y,Yan X L.Ideal root architecture for plant absorption of phosphorus under interactive stress of water and phosphorus:Simulation and application[J].Chinese Science Bulletin,2001,46(8):641-646.
[4]李学恒.土壤化学[M].北京:高等教育出版社,2001.
[5]张志山,樊恒文,赵金龙,等.沙漠人工植物群落的根系分布及动态[J].中国沙漠,2006,26（4）:637-643.
[6]Marschner P,Crowley D,Yang C.Development of specific rhizosphere bacterial communities in relation to plant species,nutrition and soil type[J].Plant and Soil,2004,261:199-208.
[7]陆景陵.植物营养学[M].北京:中国农业出版社,1994.
[8]张丙乾.新疆土壤盐碱化及其防治[J].干旱区研究,1993,10(1):66-71.
[9]赵可夫,范海.盐生植物及其对盐渍生境的适应生理[M].北京:科学出版社,2005:72.
[10]李得禄,王继和,李爱德,等.3种驼绒藜属植物种子萌发期耐盐性试验研究[J].中国沙漠,2006,26（6）:72-76.
[11]张满效,陈拓,肖雯,等.不同盐碱环境中宁夏枸杞叶生理特征和RAPD分析[J].中国沙漠,2005,25（3）:391-396.
[12]Kuchenbuch R,Jungk A.A method for determining concentration profiles at the soil-root interface by thin slicing rhizosphere soil[J].Plant and Soil,1982,68:391-394.
[13]南京农业大学.土壤农化分析(第二版)[M].北京:农业出版社,1990.
[14]张福锁.植物根引起的根际pH值改变的原因及效应[J].土壤通报,1993,24(1):43-45.
[15]Sarker A N,Wynjones R G.Effect of rhizosphere pH on the availability and uptake of Fe,Mn,Cu and Zn[J].Plant and Soil,1992,66:361-372.
[16]张福锁,曹一平.根际动态过程与植物营养[J].土壤学报,1992,29(3):239-250.
[17]Arienzo M,Meo V D,Adamo P,et al.Investigation by electro-ultrafiltration on N and P distribution in rhizosphere and bulk soil of fieldgrown corn[J].Australian Journal of Soil Research,2004,42(1):49-57.
[18]张学利,杨树军,刘亚萍,等.章古台固沙林主要树种根际土壤性质研究[J].中国沙漠,2004,24（1）:72-76.
[19]南忠仁,李吉均.干旱区土壤小麦根系界面Pb、Ni行为的环境影响——以甘肃省白银市区污灌耕作土为例[J].中国沙漠,2001,21（1）:34-38.
[20]Darrah P R.The rhizosphere and plant nutrition:a quantitative approach[J].Plant and Soil,1993,156:1-20.
[21]李加宏.土壤-作物根际系统中离子的迁移[J].土壤学报,1998,35(2):186-194.
[22]Xu G M,Zhang Y P,Sun B H.Phosphate distribution and moment in soil-root interface zone:dynamics[J].Pedosphere,1995,5(4):349-355.
[23]Gahoonia T S,Asmar F,Giese H,et al.Root-released organic acid and phosphorus uptake of two barley cultivars in laboratory and field experiments[J].European Journal of Agronomy,2000(12):281-289.
[24]史瑞和.植物营养原理[M].南京:江苏科学技术出版社,1989:92-93.
[25]郭朝晖,张杨珠,黄子蔚.根际微域营养研究进展[J].土壤通报,1999,30（2）:85-88.
[26]Philippe H,Claude P,Benoit J.Rhizosphere:A new frontier for soil biogeochemistry[J].Journal of Geochemical Exploration,2005,88:210-213.
[27]裴世芳,傅华,陈亚明,等.放牧和围封下霸王灌丛对土壤肥力的影响[J].中国沙漠,2004,24（6）:763-767.