吉林省中部黑土区黑土土壤酸度变化对磷酸一铵的响应机制

Response Mechanism of Soil Acidity Changes to Monoammonium Phosphate in Black Soil Region of Central Jilin Province

在吉林省长春市农安县采集黑土土壤样品,通过室内土柱淋溶试验模拟施入磷酸一铵对土壤阳离子交换量、交换性盐基离子释放、酸度等的影响。结果表明:土壤中施入磷酸一铵后,K^(+)、Na^(+)、Ca^(2+)、Mg^(2+)盐基离子淋出总量随着淋洗次数增加而增加,但每个离子淋出总量不同。黑土中Ca^(2+)的淋失量最大,pH在淋洗初期呈下降趋势,但随着淋洗次数增加淋出液pH缓慢升高。K^(+)、Ca^(2+)以及Mg^(2+)对磷酸一铵最为敏感,即在磷酸一铵处理下淋出量高于其他2个处理,Na^(+)对磷酸二铵最为敏感。BS1中磷酸一铵作为淋入液时,4种盐基离子淋失总量为磷酸二铵的3.9倍,而蒸馏水作为淋入液时是磷酸二铵的2.0倍;BS2中磷酸一铵的处理盐基淋失总量为磷酸二铵处理的3.6倍,是蒸馏水处理的2.3倍;BS3中则是3.8,2.4倍。黑土在经过淋洗后,有机质呈下降趋势,在蒸馏水淋洗后有机质下降最少,黑土中磷酸二铵的处理下降最多,下降了4~5 g/kg。黑土淋洗后阳离子交换量:蒸馏水>磷酸二铵>磷酸一铵,淋洗后土壤的游离氧化铁变化为蒸馏水>磷酸二铵>磷酸一铵。土壤淋洗后交换性阳离子在蒸馏水处理下改变幅度不大,磷酸一铵降低的幅度最大,对交换性盐基离子影响最大。黑土施用磷酸一铵淋洗后土壤pH反而升高,施用蒸馏水和磷酸二铵后土壤pH升高。

Black soil samples were collected in Nong'an county,Changchun city,Jilin province,and the effects of monoammonium phosphate application on soil cation exchange capacity,exchangeable base ion release,and acidity changes were simulated by an indoor soil column leaching experiment.The results show:After the application of monoammonium phosphate in the soil,the total leaching of K^(+),Na^(+),Ca^(2+)and Mg^(2+)base ions increases with the increase of the number of leaching,but the total leaching of each ion is different.The leaching amount of Ca^(2+)in black soil is the largest,and the pH shows a downward trend at the beginning of leaching,but the pH of the leaching solution increases slowly with the increase of the number of leaching.K^(+),Ca^(2+)and Mg^(2+)are most sensitive to monoammonium phosphate,that is,the amount of leaching under monoammonium phosphate treatment is higher than other two treatments,and Na^(+)is most sensitive to diammonium phosphate.When monoammonium phosphate is used as the leaching solution in black soil BS1,the total amount of four base ions lost is 3.9 times that of diammonium phosphate,while the total amount of four base ions lost is 2.0 times that of diammonium phosphate when distilled water is used as the leaching solution.The total leaching of monobasic ammonium phosphate in black soil BS2 is 3.6 times that of diammonium phosphate and 2.3 times that of distilled water.In black soil BS3,it is 3.8 and 2.4 times,respectively.After the black soil was washed,the organic matter showed a downward trend.After the distilled water was rinsed,the organic matter decreased the least.The treatment of diammonium phosphate in the black soil decreased by about 4-5 g/kg at most.The amount of cation exchange after black soil leaching:distilled water>diammonium phosphate>monoammonium phosphate.The change of free iron oxide in soil after leaching was:distilled water>diammonium phosphate>monoammonium phosphate.After the soil was rinsed,the exchangeable cations did not change much under the treatment of distilled water,monoammonium phosphate decreased the most,and had the greatest effect on the exchangeable base ions.The pH of black soil increased after being rinsed with monoammonium phosphate,and the soil pH increased with distilled water and diammonium phosphate.