摘要
三江平原大规模集约化农业生产活动破坏了土壤养分平衡,加快了营养物质输移过程,而沟渠土壤中高有机物含量有利于营养元素的化学循环.为了研究冻融过程及添加不同比例生物炭对沟渠土壤氮素淋失的影响效果,本研究采用室内土柱模拟淋溶方法,探究了冻融过程及添加不同比例生物炭土壤对淋溶液中铵态氮(NH^+_4-N)和硝态氮(NO^-_3-N)淋失量的影响规律.实验采用400℃烧制的玉米秸秆生物炭,分别按照炭土质量比0、0.75%、1.50%、3.00%的比例施用于沟渠土壤中.结果表明:施加生物炭加快了溶液的淋溶速率;施加生物炭能够增加土壤对氮素的固持,且不同配比生物炭的土壤对铵态氮的固持能力优于硝态氮,添加0.75%生物炭的土壤对硝态氮表现出较好的固持能力;冻融条件下土壤氮素的淋失有所增加,生物炭对氮素的固持能力随着冻融次数的增加也有所降低,在本实验中,当冻融频次为1时,冻融过程对生物炭固持土壤氮素能力的抵消作用最大.
Intensive agricultural activities have altered soil nutrient balance in the Sanjiang plain, leading to subsequent accelerated nutrient transport. However, the high organic matter content in ditch soil is beneficial to chemical cycles of nutrient elements. In order to elucidate effects of freeze-thaw processes and different biochar addition rates on soil nitrogen leaching in agricultural ditches, this study conducted laboratory soil column leaching experiments and characterized leaching of ammonium nitrogen and nitrate nitrogen. Corn-stalk biochar, obtained at 400 ℃, was applied to soil collected from the depth of 0~20 cm in drainage ditch using biochar/soil ratio of 0, 0.75%, 1.50%, and 3.00%. The results showed that, biochar addition accelerated solution leaching and facilitated nitrogen retention in soils. ammonium nitrogen retention in soils with biochar addition at different rates was greater compared with nitrate nitrogen. The greatest nitrate nitrogen retention was observed in soils inclusive of 0.75% biochar. Soil nitrogen leaching increased after enduring freeze-thaw cycles. Nitrogen retention in soils with biochar addition reduced with increasing frequency of freeze-thaw cycles, decrements being negatively correlated with the number of times of freeze-thaw cycles. The magnitude of soil nitrogen retention reduction was greatest after one freeze-thaw cycle.
作者
邬真真
程红光
王建童
程千钉
路路
孙海旭
WU Zhenzhen;CHENG Hongguang;WANG Jiantong;CHENG QiANDing;LU Lu;SUN Haixu(School of Environment,Beijing Normal University,Beijing 100875;Taiji Computer Corporation Limited,Beijing 100102;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101)
出处
《环境科学学报》
CAS
CSCD
北大核心
2019年第4期1295-1302,共8页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.41471396
41771496)
国家自然科学基金青年科学基金(No.41701559)
中国博士后科学基金(No.2016LH0002
2017M620890)
关键词
冻融
生物炭
氮淋失
铵态氮
硝态氮
freeze-thaw
biochar
nitrogen leaching
ammonium nitrogen
nitrate nitrogen
