摘要
[目的]探究生物炭配施化肥对不同粒级团聚体中微生物量碳、氮(MBC、MBN)含量和胞外酶活性的影响,分析影响团聚体胞外酶活性变化的主控因素,为提升土壤质量提供科学依据。[方法]田间微区试验在河南现代农业研究基地进行,供试土壤为石灰性潮土。设置4个处理:不施肥(CK)、单施化肥(NPK)、单施生物炭(BC)和生物炭配施化肥(BC+NPK),生物炭是以花生壳为原料高温裂解制备而成,仅在试验开始前施用一次,化肥每季均施用。试验开始于2017年小麦季,于2019年9月玉米收获后采集耕层土壤样品,测定土壤养分含量,分析各粒径团聚体MBC、MBN含量和酶活性。[结果]与CK相比,NPK处理可显著提高耕层土壤有效磷、速效钾和硝态氮含量,BC处理可显著提高有机碳和全氮含量,BC+NPK处理则显著提高了以上各指标含量。与CK相比,BC处理显著降低了粒径2~0.25 mm团聚体MBN含量,并明显增加了该粒径的MBC/MBN值;BC+NPK处理显著增加了粒径>2 mm和0.25~0.053 mm团聚体中MBC含量(增幅分别为59.57%和34.68%),也增加了耕层土壤、粒径>2 mm和2~0.25 mm团聚体中MBN含量(增幅分别为17.33%、42.24%和19.28%)。与CK相比,NPK、BC和BC+NPK处理均显著增加粒径>2 mm团聚体微生物熵,而BC和BC+NPK处理则显著降低了耕层土壤、粒径2~0.25 mm和0.25~0.053 mm团聚体微生物熵。与CK相比,NPK和BC+NPK处理均显著提高了粒径2~0.25 mm和0.25~0.053 mm团聚体中β-葡糖苷酶、β-纤维二糖苷酶、α-葡糖苷酶和β-木糖苷酶活性;在粒径>2 mm团聚体中,仅BC+NPK处理明显提高了该四种酶的活性。与CK相比,NPK和BC+NPK处理均明显提高了粒径>2 mm团聚体中脲酶活性及粒径0.25~0.053 mm团聚体中乙酰氨基葡糖苷酶活性,仅BC+NPK处理可显著提高粒径>2 mm和0.25~0.053 mm团聚体中亮氨酸氨基肽酶活性。团聚体酶活性变化与MBC、MBN含量以及MBC/MBN值显著相关。粒径>2 mm团聚体中酶活性变化与微生物熵、全氮和M BC含量均显著相关,粒径2~0.25 mm团聚体中酶活性变化与MBC/MBN值显著相关,而粒径0.25~0.053 mm团聚体中酶活性变化与MBC含量显著相关。[结论]生物炭与化肥配施有利于土壤碳的固存,改善土壤微环境,提升土壤质量,且生物炭添加到土壤中有较长的后效。
[Objectives]To provide a scientific basis for improving soil quality,we investigated the effects of biochar(BC)on microbial biomass carbon and nitrogen contents and extracellular enzyme activities within soil aggregates,and analyzed the main factors that drive changes in enzyme activities within aggregates.[Methods]A 2-year field experiment was conducted in Henan Modern Agricultural Research Base with four treatments:no fertilizer(CK),chemical fertilizers(NPK),biochar(BC),biochar plus chemical fertilizers(BC+NPK).Biochar was prepared by pyrolyzing peanut shells and was applied only once at the beginning of the experiment.NPK fertilizers were applied in each season.Soil samples of the plough layer were collected for determination of nutrient contents,microbial biomass carbon(MBC),microbial biomass nitrogen(MBN)and enzyme activities in soil aggregates.[Results]1)Compared with CK,NPK increased soil available phosphorus,available K,and NO3–-N,BC increased SOC and total N contents,and BC+NPK increased all the aforementioned indicators.2)Compared with CK,BC reduced MBN in size 2–0.25 mm aggregate and increased MBC/MBN ratio in 2–0.25 mm aggregate.Compared with CK,BC+NPK increased MBC in size>2 mm and 0.25–0.053 mm aggregates by 59.57%and 34.68%,respectively,and increased MBN in the plough layer soil,size>2 mm and 2–0.25 mm aggregates by 17.33%,42.24%and 19.28%,respectively.Compared with CK,NPK,BC,and BC+NPK treatments increased MBC/SOC in size>2 mm aggregate,but BC and BC+NPK reduced MBC/SOC in plough layer soil,size 2–0.25 mm and 0.25–0.053 mm aggregates.3)Compared with CK,NPK,BC+NPK increasedβ-glucosidase,β-cellobiosidase,α-glucosidase,andβ-xylosidase activities in size 2–0.25 mm and 0.25–0.053 mm aggregates,whereas only BC+NPK increased the activities of aforementioned four enzymes in size>2 mm aggregate.Compared with CK,NPK and BC+NPK increased urease activity in size>2 mm aggregate and N-acetylglucosaminidase activities in size 0.25–0.053 mm aggregates.Only BC+NPK treatment increased L-leucine aminopeptidase activities in size>2 mm and 0.25–0.053 mm aggregates.Enzyme activities in soil aggregates significantly related to MBC,MBN and MBC/MBN ratio.Enzyme activities in size>2 mm aggregate significantly correlated with MBC/SOC,TN and MBC contents,while enzyme activities in size 2–0.25 mm and 0.25–0.053 mm aggregates significantly correlated with MBC/MBN ratio and MBC content,respectively.[Conclusions]Combined application of biochar and chemical fertilizers is suitable for soil carbon sequestration,and soil micro-environment and soil quality improvment,and application of biochar has a longer effect on calcareous soil.
作者
张帅
成宇阳
吴行
郑琴
王秀斌
张水清
ZHANG Shuai;CHENG Yu-yang;WU Hang;ZHENG Qin;WANG Xiu-bin;ZHANG Shui-qing(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China;Institute of Plant Nutrition and Environmental Resources Science,Henan Academy of Agricultural Sciences,Zhengzhou 450002,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2021年第3期369-379,共11页
Journal of Plant Nutrition and Fertilizers
基金
国家重点研发计划项目(2018YFD0200500)。
关键词
潮土
土壤团聚体
生物炭
微生物量碳氮
土壤酶活性
calcareous soil
soil aggregate
biochar
microbial biomass carbon and nitrogen
soil enzyme activity
