不同水分培养下添加生物质炭湿地土壤pH的变化特征

The Effects of Biochar on Wetland Soil pH under Different Water Treatments

[目的]研究在不同水分条件下添加生物质炭后湿地土壤pH的变化特征。[方法]以巢湖十五里河河口湿地土壤为研究对象,采用室内土柱模拟试验,研究在干湿交替(J)、75%田间持水量(75%)和淹水(Y)3种水分条件下,添加不同条件(350℃与600℃、洗涤与未洗涤)制备的生物质炭对湿地土壤pH的影响。[结果]随着培养时间的延长,在干湿交替和75%田间持水量条件下,对照组土样pH先降低后升高,加入生物质炭可以降低土样的pH,增加其酸度,且干湿交替时培养时间越长,降低作用越明显;淹水培养土壤pH变化趋势呈"W"型,添加生物质炭对其有影响,但在不同培养周期作用不同。培养期间,对照组土壤pH为CKY>CKJ>CK75%。添加生物质炭后,土壤pH为Y>J和75%,且水分培养条件相同,添加同一温度制备的洗涤与未洗涤生物质炭土壤pH变化趋势相同。[结论]该研究为利用生物质炭进行土壤酸碱度改良提供参考。

[Objective]To study the change characteristics of soil pH in wetlands under different water conditions.[Method]Soils were collected from estuary wetland of Shiwuli River in the Chaohu Lake region.Biochars with four treatment types(washed and unwashed;350℃and 600℃)were added to wetland soils,and the experiment sets three kinds of water treatment,dry-wet alternate(J),75%field capacity(75%)and flooded(Y).The soil column simulated experiments were adopted to measure and study the effect of biochar on pH of wetland soil under three different water treatments for six periods(120 days every period).[Result]As time went on,soil pH in the control group decreased first and then increased under the condition of dry-wet alternate(J)and 75%field capacity(75%).And adding biochar could reduce pH of the soil sample and increase its acidity.The trend of soil pH change in flooded culture was"W",and the addition of biochar had influence on it,but there was no uniform rule.During the whole period,the soil pH of the control group was CKY>CKJ>CK75%.After adding biochar,the pH of soil sample was shown as:Y>J and 75%.The trend of soil pH change adding washed and unwashed biochar produced at the same temperature was the same under the same water condition.[Conclusion]The study provides reference for the improvement of soil acidity and alkalinity using biomass charcoal.