为研究生物质炭中盐基离子存在形态及其与改良酸性土壤的关系，通过厌氧热解的方法于300、500和700 ℃下制备了玉米秸秆炭。考察了热解温度对玉米秸秆炭水溶性、交换性和盐基总量的影响。采用室内培养的方法考察了添加玉米秸秆炭对酸性土壤的改良效果。结果表明：热解温度影响玉米秸秆炭各形态盐基离子含量，玉米秸秆炭总K、总Na、总Ca、总Mg、水溶性K、水溶性Na、水溶性Ca、交换性Ca和交换性Mg含量随热解温度升高显著增加；水溶性Mg和交换性K含量随热解温度升高先增加后下降。玉米秸秆炭中的K和Na主要以水溶态存在，约40% 的Ca和30% 的Mg以交换态存在，约50% 的Ca和70% 的Mg以其他形态(主要为难溶态)存在。添加玉米秸秆炭能极显著提高酸性土壤pH和降低土壤交换性Al³⁺ 含量，提高和降低幅度随热解温度升高极显著增加。总K + 总Na + 总Ca + 总Mg含量可以作为衡量玉米秸秆炭提高酸性土壤pH能力的间接指标。添加玉米秸秆炭能极显著提高土壤交换性K、Na和Mg含量，能显著提高交换性Ca和总盐基离子含量。玉米秸秆炭总K和总Na含量是提高土壤交换性K和Na含量的决定因素，交换性Ca含量在提高土壤交换性Mg和交换性盐基总量中起决定作用。

Corn straw biochars were prepared under 300, 500 and 700 ℃ respectively by using oxygen-limited pyrolysis method. The effects of pyrolysis temperature on the contents of water soluble, exchangeable and total base cations in corn straw biochars were studied. The amelioration effects of corn straw biochars on an acid soil and the relationships between different forms of base cations and soil acidity amelioration were studied using an indoor incubation experiment for one-year time. The results showed that pyrolysis temperature had significant effects on the contents of different forms of base cations in corn straw biochars. The contents of total K, Na, Ca and Mg, water soluble K, Na and Ca, exchangeable Ca and Mg increased with increasing pyrolysis temperature. Water soluble Mg and exchangeable K first increased and then decreased with increasing pyrolysis temperature. The main forms of K and Na in corn straw biochars were water soluble forms, about 40% Ca and 30% Mg existing in exchangeable forms, about 50% Ca and 70% Mg existing in other forms (mainly in insoluble forms). Corn straw biochar can increase acid soil pH and decrease soil exchangeable Al³⁺ significantly. The extent of increasing or decreasing increased significantly with increasing pyrolysis temperature. The sum content of total K+ total Na+ total Ca+ total Mg can be an indirect indicator for corn straw biochar’s capacity of raising acidic soil pH. The contents of soil exchangeable K, Na, Ca, Mg and total base cations were increased significantly by the addition of corn straw biochar. The total content of K or Na in corn straw biochar dominates the increase of soil exchangeable K or Na content. The content of exchangeable Ca in corn straw biochar dominated the increase of soil Mg and total base cations.

S156.6

甘肃省农业科学院农业科技创新专项计划项目(2017GAAS26)、甘肃省农业科学院中青年基金项目(2015GAAS32)和甘肃省新型肥料创制工程实验室项目(甘发改高技【2016】1099号)资助。