摘要
为模拟植物根系分泌主要有机酸(OA、CA)对土壤钾素的活化机理,采用土壤连续培养法,研究氢离子与有机配体对褐土钾素的活化能力及有机酸活化土壤钾素的化学机理。结果表明,用不同试剂连续培养土壤25天,各处理速效钾含量表现为OA 157.65 mg/kg最高,CA-Na 98.49 mg/kg最低,处理间差异极显著。在溶液浓度相同时,氢离子的酸化作用与有机配体的络合作用之间没有作用顺序差异。研究认为,土壤钾素活化过程是先由有机酸络合溶解后酸性水解的循环过程,有机酸浓度高时,土壤钾活化主要取决于溶液酸度;有机酸浓度低时,土壤主要依赖有机物的络合作用释放钾。在实际生产中将应增加根际土壤中具有络合作用物质的含量作为营养施肥、选育品种的理论依据。
In order to simulate the mechanism of the main organic acids in root exudates （oxalic acid and citric acid） releasing potassium from soil, the difference in ability to enhance the available potassium in cinnamon soil of H＋ and organic ligands was studied and the chemical mechanism was analyzed through an experiment in which soil samples were continuous cultured. The results showed that, soil samples were cultured for 25 days in different reagents, the available potassium content in each treatment was higher after adding oxalic acid （157.65 mg/kg） and lower after adding sodium citrate （98.49 mg/kg）, the differences among the varieties were significant. There was no difference in acidification and complexation under the same add concentration. The research suggested that available potassium releasing mainly depend on acidity of solution when the solution with high concentration but complexation of organic ligands turned dominant as the solution concentration was low. The process of available potassium releasing from soil is a cyclic process in which soil was acidified after complexed by organic acids. It should be considered as a theoretical basis how to increase the content of matter with complexation in rhizosphere soil for fertilization and breeding.
出处
《土壤》
CAS
CSCD
北大核心
2015年第1期74-79,共6页
Soils
基金
中国烟草总公司科技重点项目(110201002008)资助
关键词
褐土
钾释放
酸化作用
络合作用
化学模拟
有机酸
Cinnamon soil
Potassium release
Acidification
Complexation
Chemical simulation
Organic acids
