长期秸秆配施化肥下土壤团聚体碳氮分布、微生物量与小麦产量的协同效应  

Synergistic Effects of Organic Carbon and Nitrogen Content in Water-Stable Aggregates as well as Microbial Biomass on Crop Yield Under Long-Term Straw Combined Chemical Fertilizers Application

作　　者：韩紫璇 房静静 武雪萍[1] 姜宇[3] 宋霄君 刘晓彤 HAN ZiXuan;FANG JingJing;WU XuePing;JIANG Yu;SONG XiaoJun;LIU XiaoTong(State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China(the Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences),Beijing 100081;College of Resource Environment and Tourism,Capital Normal University,Beijing 100048;Heilongjiang Academy of Agricultural Sciences/Heihe Branch National Soil Quality Aihui Observation and Testing Station,Heihe 164300,Heilongjiang)

机构地区：[1]北方干旱半干旱耕地高效利用全国重点实验室(中国农业科学院农业资源与农业区划研究所),北京100081 [2]首都师范大学资源环境与旅游学院,北京100048 [3]黑龙江省农业科学院/黑河分院国家土壤质量爱辉观测试验站,黑龙江黑河164300

出　　处：《中国农业科学》2023年第8期1503-1514,共12页Scientia Agricultura Sinica

基　　金：中国农业科学院科技创新工程(CAAS-ZDRW202202);国家重点研发计划(2018YFD0200408、2016YFD0300804);国家科技支撑计划(2015BAD22B03)。

摘　　要：【目的】研究秸秆配施化肥对暗棕壤团聚体组成、团聚体碳氮含量、土壤微生物量特征及小麦产量的影响,揭示长期秸秆配施化肥下土壤肥力和生产力的协同提升机制。【方法】依托长期定位40年施肥试验,选取4个处理:单施化肥(NP)、秸秆配施化肥(S+NP)、秸秆配施1/2化肥(S+1/2NP)、秸秆配施1/4化肥(S+1/4NP),其中秸秆为麦秸隔年还田,用量为3000 kg·hm^(-2),氮磷化肥用量为150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)。采集0—20 cm土层土样,利用湿筛法得到不同粒级的水稳性团聚体,测定团聚体中有机碳(SOC)、氮含量及土壤微生物量碳(SMBC)、微生物量氮(SMBN)含量。【结果】(1)长期秸秆配施化肥显著降低土壤容重并提高了团聚体稳定性,和NP相比,S+NP处理土壤容重降低4.7%,>2 mm团聚体含量、平均重量直径(MWD)和几何重量直径(GWD)分别提升254.4%、76.5%和91.3%。(2)S+NP、S+1/2NP处理>2 mm团聚体百分含量、MWD和GWD显著高于S+1/4NP,分别增加了49.1%—52.4%,19.43%—22.4%和24.2%—33.3%。(3)S+NP、S+1/2NP、S+1/4NP和NP相比增加了>2 mm和>0.25 mm团聚体对土壤有机碳、全氮贡献率,并显著提高全土SOC、SMBC和SMBN含量;其中,SOC含量在S+NP中最高,比S+1/2NP、S+1/4NP高6.3%和12.6%。(4)产量表现为S+NP>NP>S+1/2NP>S+1/4NP处理,S+NP比减施化肥处理提高小麦产量28.6%—47.5%。(5)土壤团聚体稳定性、SOC含量及小麦产量之间有较好的相关性,>2 mm和>0.25 mm团聚体含量、MWD和GWD分别与全土SOC含量及小麦产量呈显著或极显著正相关。【结论】暗棕壤地区在长期秸秆还田条件下,配施化肥量150 kg N·hm^(-2)、150 kg P2O5·hm^(-2)时能提高土壤团聚体稳定性、有机碳含量、微生物生物量和小麦产量,最大化实现土壤结构改良、肥力提升和作物增产的协同效应。【Objective】The effects of long-term straw combined application of chemical fertilizers on the content of aggregates,distributions of aggregate-associated organic carbon and nitrogen,and soil microbial biomass were studied to reveal the promotion of soil fertility and productivity.【Method】Soil samples were collected from a 40-year long-term experiment.The research was conducted with 4 treatments:pure chemical fertilizer(NP),straw with chemical fertilizer(S+NP),straw with 1/2 chemical fertilizer(S+1/2NP),and straw with 1/4 chemical fertilizer(S+1/4NP),and the straw was returned with the amount of 3000 kg·hm^(-2),chemical fertilizer NP was pure N 150 kg·hm^(-2) and P2O5150 kg·hm^(-2) conducted.All soils samples were separated into four aggregate-size classes(>2 mm,0.25-2 mm,0.053-0.25 mm,and<0.053 mm)by wet sieving.Organic carbon and total nitrogen content of aggregates and soil microbial biomass content were measured.【Result】(1)Long-term application of chemical fertilizers with straw reduced soil bulk density,while improved the stability of aggregates.Compared with NP,the bulk density of S+NP decreased by 4.7%,while the proportion of aggregates>2 mm in size,the average weight diameter(MWD)and geometric weight diameter(GWD)increased by 254.4%,76.5%and 91.3%,respectively.(2)In the three chemical fertilizers combined with straw return,the percentage of aggregates>2 mm,MWD and GWD under S+NP and S+1/2NP were significantly increased by 49.1%-52.4%,19.43%-22.4%and 24.2%-33.3%,compared with S+1/4NP,respectively.(3)Compared with NP,S+NP,S+1/2NP and S+1/4NP increased the contribution rate of aggregates>2 mm and>0.25 mm to SOC and total nitrogen,and significantly improved the SOC,SMBC and SMBN content in bulk soil.Among them,the SOC content was the highest under S+NP,which was 6.3%and 12.6%higher than that under S+1/2NP and S+1/4NP,respectively.(4)The yield was showed that S+NP>NP>S+1/2NP>S+1/4NP,and S+NP increased wheat yield by 5.83%-83.6%compared with other treatments.(5)Positive correlation was revealed be

关 键 词：秸秆还田 化肥 暗棕壤 水稳性团聚体 碳氮含量 微生物生物量 小麦产量 

分 类 号：S153.6[农业科学—土壤学] S512.1[农业科学—农业基础科学]