茶树根系分泌物对土壤中磷、铝形态转化机制研究

发布时间：2018-02-14 03:41

本文关键词： 根系分泌物磷形态铝形态转化机制　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：茶树是典型的富铝喜酸植物,而在酸性条件下,土壤中的磷很容易被固定,但目前对茶园土壤铝、磷相互作用的机理不是很清楚。因此,为了弄清茶园土壤铝、磷相互作用的过程与机理,研究了茶树根系分泌物作用下土壤中磷、铝形态转化过程。本研究采用浸提与培养实验方法,研究了茶树根系分泌物对第四纪红土发育的红泥土和花岗岩风化物发育的麻砂土中磷、铝形态变化的影响。主要研究结果如下：1磷形态转化实验结果表明：加入根系分泌物培养土壤中四种磷形态含量发生了明显变化,而水培对照土壤中四种磷形态含量几乎没有变化,前者Al-P和O-P含量减少,Fe-P和Ca-P含量增加,说明了根系分泌物对土壤中磷形态转化影响。2茶树根系分泌物对土壤磷形态转化培养实验表明：加入根系分泌物培养后,随时间变化土壤中不同磷形态含量出现了不同的变化趋势。土壤中A1-P含量随培养时间增加而减少,Fe-P含量随培养时间增加而增加,说明在根系分泌物作用下土壤中Al-P逐渐向其他磷形态转化,其他磷形态则逐渐向Fe-P转化,O-P和Ca-P则变化趋势不明显则表明在根系分泌物环境下这两种磷形态相对稳定,影响较小。四种磷形态相关性分析结果表明,两种供试土壤中Al-P和Fe-P均在0.01水平上显著相关,其他而磷形态含量之间相关不显著,从而可以推断在根系分泌物作用下土壤中部分Al-P可能向Fe-P发生转化。3茶树根系分泌物对土壤铝形态转化培养实验表明：随培养时间的变化土壤中铝形态出现不同的转化机制。土壤中腐殖酸铝含量随培养时间的增加而逐渐增加,说明在根系分泌物能够促进土壤中其他铝形态向腐殖酸铝进行转化。通过对比四种铝形态含量的变化率,可以看出土壤中铝形态转化方向不是固定的,无机吸附态铝表现出先减后增的变化趋势,即无机吸附态铝先向其他铝形态进行转化,到达某一临界点后其他铝形态再转化为无机吸附态铝。
[Abstract]:Tea is a typical aluminophilic plant, and phosphorus in the soil is easy to be fixed under acidic conditions, but the mechanism of the interaction of aluminum and phosphorus in tea garden soil is not very clear at present. Therefore, in order to understand the aluminum in tea garden soil, The process and mechanism of phosphorus interaction, the transformation process of phosphorus and aluminum in soil under the action of root exudates of tea plant were studied. The phosphorus in tea root exudates from red soil developed in Quaternary red soil and hemp sand developed by granite weathering was studied. The main results are as follows: the contents of four phosphorus forms in the soil cultured with root exudates have changed obviously, the main results are as follows: 1. The contents of Al-P and O-P decreased and the contents of Fe-P and Ca-P increased. The effects of root exudates on the transformation of phosphorus forms in soil were discussed. The content of A1-P in soil decreased with the increase of culture time, and the content of Fe-P increased with the increase of incubation time. The results indicated that under the action of root exudates, Al-P was gradually transformed to other phosphorus forms, while other phosphorus forms were gradually transformed to Fe-P, and Ca-P and O-P were not changed obviously, which indicated that the two phosphorus forms were relatively stable in root exudate environment. The results of correlation analysis of four phosphorus forms showed that Al-P and Fe-P were significantly correlated at 0.01 level, while the other P forms were not significantly correlated with each other. It can be concluded that part of Al-P in soil may be transformed to Fe-P under the action of root exudates. 3 the experiment of transformation of Al forms in soil by root exudates of tea plants shows that: with the change of culture time, aluminum forms in soil appear different. The content of aluminum humate in soil increased with the increase of culture time. The results show that the root exudates can promote the transformation of other aluminum forms into aluminum humate in soil. By comparing the change rates of the four aluminum species, we can see that the transformation direction of aluminum forms in soil is not fixed. The inorganic adsorbed aluminum shows the tendency of decreasing first and then increasing, that is, the inorganic adsorbed aluminum transforms to other aluminum forms first, and then to inorganic adsorbed aluminum after reaching a certain critical point.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S571.1;S153

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