养分缺乏下外源有机酸对暗棕壤磷有效性及落叶松幼苗吸收积累磷的影响  

Effects of Exogenous Organic Acids on P Availability of Dark Brown Forest Soils and P Absorption and Accumulation in Larix olgensis Seedlings with Nutrient Deficiency

作　　者：崔福星[1,2] 宋金凤[1] 杨迪[1] 

机构地区：[1]东北林业大学,哈尔滨150040 [2]黑龙江省科学院自然与生态研究所,哈尔滨150040

出　　处：《水土保持学报》2012年第6期116-121,共6页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(30901145);中央高校基本科研业务费专项资金资助项目(DL12CA01)

摘　　要：用不同比例A1和B层暗棕壤混合(A1∶B=1∶2)制造土壤养分缺乏条件,栽植落叶松幼苗,通过模拟我国东北林区代表性森林凋落物淋洗液中有机酸的种类和数量,系统研究养分缺乏下,不同浓度外源有机酸对暗棕壤磷有效性和落叶松幼苗吸收、运输磷素养分的影响及机理,以探讨利用有机酸提高养分缺乏下落叶松幼苗抗土壤贫瘠能力的可行性及机制。结果表明,A1层与B层混合土壤速效磷含量降低,落叶松幼苗根系和叶片磷累积量和磷吸收效率降低,但磷利用效率增加。外源有机酸处理后,混合土壤的速效磷含量有不同程度提高,3种有机酸的作用强弱表现为琥珀酸>柠檬酸>草酸,一般以浓度5.0mmol/L和处理20d时提高效果最显著。有机酸不同程度提高了根系和叶片的磷累积量和磷吸收效率,但降低了磷利用效率。有机酸对磷累积量和磷吸收效率的提高程度因处理时间、有机酸浓度和种类而异:对于根系,20d和30d的结果高于10d,叶片则为10d和20d的结果高于30d,说明处理前期磷被吸收后向叶片的转移量较多,而后期则更多地在根中积累;3种有机酸大多在浓度为10.0mmol/L时提高幅度最大;不同有机酸的促进程度为琥珀酸>柠檬酸>草酸。因此,外源有机酸能通过提高落叶松幼苗对养分缺乏土壤中磷的吸收能力,促进磷的积累,进而提高苗木对养分缺乏土壤的耐性和适应能力。Different proportion of A1 and B horizons dark brown forest soils（A1∶B=1∶2） were utilized to set the soil nutrient deficient conditions,and Larix olgensis seedlings were cultivated.By simulating organic acids concentrations in forest litter leachates of northeast China,the effects and mechanism of different concentrations of organic acid solutions on phosphorus（P） availability of dark brown forest soils and P absorption of Larix olgensis seedlings with nutrient deficiency were studied.The results showed that,comparing with those of A1 horizon soil,available P contents of A1 and B horizons mixed decreased,P accumulation and efficiency of P uptake in root and leaves of Larix olgensis seedlings also decreased,but efficiency of P utilization increased.After treatments of exogenous organic acids,available P contents of mixed soils increased,the impact sequence of different organic acids were succinic acid 〉citric acid〉 oxalic acid,the concentration of 5.0 mmol/L had the best function,and the best effect of organic acids was at 20 d.Organic acids also increased P accumulation and efficiency of P uptake in roots and leaves of Larix olgensis seedlings,but efficiency of P utilization decreased.The impact strength of organic acids on P accumulation and efficiency of P uptake varied with treatment time,type and concentration of organic acids.The results of 20 d and 30 d in roots were higher than those of 10 d,however,the results of 10 d and 20 d in leaves were higher than those of 30 d,thus,at the earlier stage of organic acids treatments,more P absorbed were transferred to leaves,and at the later stage more P were accumulated in roots.The concentration of 10.0 mmol/L had the best function,and the impact sequence of different organic acids were succinic acid 〉citric acid 〉oxalic acid.Organic acids might contribute to P absorption and accumulation by Larix olgensis seedlings,finally increased the adaptability and endurance of Larix olgensis seedlings to nutrient deficient soils.

关 键 词：养分缺乏 有机酸 暗棕壤 落叶松 磷 

分 类 号：S158.3[农业科学—土壤学]