摘要
【目的】以我国黄淮平原粮食主产区潮土为研究对象,通过探讨小麦-玉米轮作体系下,不同小麦播量与减量氮肥下,土壤微生物量碳、氮和酶活性的差异和变化,以了解小麦播量和氮肥对土壤微生物量的影响。【方法】试验设4个处理,分别为:(1)常规播量+常规施氮肥(CK);(2)增播30%+常规施氮(T1);(3)增播30%+减氮20%(T2);(4)常规播量+减氮20%(T3)。2016—2018年3季作物收获后,采取不同土层土壤,测定有机碳(SOC)、全氮(TN)、微生物量碳氮(SMBC、SMBN)及其相关酶活性。【结果】总体上,3季中各处理土壤微生物量碳氮、有机碳、全氮以及3种酶活性均随土壤深度增加而下降。常规施肥处理(CK和T1)的SMBC的含量在2017年的小麦和玉米季0—20 cm土层以及2018年小麦季则0—30 cm基本表现为显著高于减氮处理(T2和T3),其中T1处理最高为170.89 mg?kg-1。SMBN与SMBC表现出类似的趋势,在3季中均以常规施肥处理显著高于减氮处理,其中CK处理的SMBN在3季中0—30 cm土层均表现较高,最高为57.24 mg?kg-1。各处理SOC含量的差异在前两季主要集中在0—20 cm土层,而第3季则集中在10—30 cm土层;其中2017年玉米季0—20 cm土层减氮处理的SOC含量显著高于常规施肥处理,以T3处理SOC含量最高,为12.85 g?kg-1。2017年小麦季各处理TN含量在0—30 cm土层基本差异不显著;而在2017年玉米季和2018年小麦季的0—20 cm土层均以CK处理TN含量显著高于其他处理,最高为1.57 g?kg-1。各处理土壤碳氮比(C/N)在2017年小麦季没有明显规律,而在2017年玉米季和2018年小麦季的0—20 cm土层基本表现为减氮处理的C/N显著高于常规施肥处理。各处理的微生物熵(Cmic/Corg)、微生物量氮/全氮(Nmic/Ntotal)分别在0.5%—2.5%、2%—6%之间,微生物量碳氮比(Cmic/Nmic)在5﹕1以下。各处理Cmic/Corg除2017年小麦季10—20 cm土层,其他作物季节和土层均表现为常规施肥处理显著高于减氮�
【Objective】The effects of wheat sowing rate and nitrogen fertilizer interaction on soil microbial biomass carbon/nitrogen(SMBC/N)and enzyme activities in the Huang-Huai Plain of China was studied,aimed to select the optimum management in this area.【Method】Field experiment was conducted,and four treatments were set as:(1)conventional seeding+conventional nitrogen fertilizer(CK);(2)30%additional seeding+conventional nitrogen application(T1);(3)30%additional seeding+20%nitrogen reduction(T2);(4)conventional seeding+20%nitrogen reduction(T3).The soil organic carbon(SOC),total nitrogen(TN),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and soil enzyme activities were measured and analyzed in different soil depths during the three crop seasons in 2016-2018.【Result】Generally,all the indexes decreased with soil depth.The SMBC was significantly higher under conventional nitrogen(N)treatments(i.e.CK and T1)than that under nitrogen reduction treatments(i.e.T2 and T3)in 0-20 cm in wheat and maize season 2017 and 0-30 cm in wheat season 2018,and the highest one was 170.89 mg?kg-1.The dynamics of SMBN was similar as SMBC,which was significantly higher under conventional N treatments than that under N reduction treatments during the all the crop seasons,and with the highest value as 57.24 mg?kg-1 under CK treatment.The differences of SOC content among treatments were focused on 0-20 cm during the first and second seasons,and10-30 cm during the third season.Therein,the SOC content under N reduction treatments was significantly higher than that under conventional N treatments,with the highest one as 12.85 g?kg-1 under T3.The TN content under all the treatments was no different in wheat season 2017,which was significantly higher under CK treatment than that under the others in 0-20 cm in maize season 2017 and wheat season 2018.The C/N was no obviously trend in wheat season 2017,while it was significantly higher under N reduction treatments in 0-20 cm during maize season 2017 and wheat season
作者
石柯
董士刚
申凤敏
龙潜
姜桂英
刘芳
刘世亮
SHI Ke;DONG ShiGang;SHEN FengMin;LONG Qian;JIANG GuiYing;LIU Fang;LIU ShiLiang(College of Resources and Environment,Henan Agricultural University,Zhengzhou 450002)
出处
《中国农业科学》
CAS
CSCD
北大核心
2019年第15期2646-2663,共18页
Scientia Agricultura Sinica
基金
国家重点研发计划重点专项项目(2016YFD0300803)
国家自然科学基金(41401327)
河南省教育厅基金(14B210024)
关键词
小麦
播种量
减氮
微生物量
土壤酶
黄淮平原
wheat
sowing rate
nitrogen reduction
soil microbial biomass
soil enzyme
Huang-Huai Plain
