高量秸秆不同深度还田对黑土有机质组成和酶活性的影响  

EFFECT OF INCORPORATION OF CROP STRAW ON COMPOSITION OF SOIL ORGANIC MATTER AND ENZYME ACTIVITY IN BLACK SOIL RELATIVE TO DEPTH AND RATE OF THE INCORPORATION

作　　者：矫丽娜[1] 李志洪[1] 殷程程[1] 王晓飞[2] 辛士颖 于磊[1] 

机构地区：[1]吉林农业大学资源与环境学院,长春130118 [2]黑龙江省科学院大庆分院,黑龙江大庆163319

出　　处：《土壤学报》2015年第3期665-672,共8页Acta Pedologica Sinica

基　　金：吉林省科技厅重点基金项目(LFGC14213);科技部丰粮工程项目(2012BAD04B02)资助

摘　　要：在田间耕作条件下黑土3个土层（0—20、20。40、40～60cm）添加4％和8％高量玉米秸秆于尼龙袋中原位培养近4年后，研究不同层次土壤秸秆转化与有机碳积累特征，以及腐殖质各组分和土壤酶活性的变化。结果表明，添加14％的秸秆量0—20、20～40和40～60cm土层有机碳分别增加31．8％、96．4％和171．1％，8％秸秆添加量分别增加了86．2％、193．5％和265．9％，增加秸秆还田深度有利于土壤有机碳的积累。0～20cm土层在无秸秆还田情况下有机碳下降了29-3％，而20～40cm土层仅下降了1．8％。土壤有机碳含量和酶活性均随秸秆添加量的增加而提高，腐殖质胡敏酸／富里酸（HA／FA）比值发生较大变化，改善了腐殖质品质。各处理腐殖酸碳（HS—C）和胡敏酸碳（HA—C）的大小为20～40cm土层〉0～20cm土层〉40～60cm土层，而40～60cm土层则更有利于富里酸碳（FA—c）的积累。土壤过氧化氢酶活性、脲酶和蔗糖酶活性分别与HA—C、FA—C含量呈极显著正相关、显著正相关。研究结果为深层秸秆还田促进土壤有机质的积累提供了理论依据。Soil organic matter, as a basic substance of soil fertility, is not only a major source of soil nutrients, but also a critical factor controlling soil physic-chemical properties, biological properties and various fertility factors. In China and other countries, soil organic matter in farmland is maintained and raised mostly through incorporation of crop straw. Humification processes of the straw incorporated, and accumulation of organic carbon, composition of soil humus and soil enzyme activities varied sharply between soils different in depth of straw incorporation, and also between soils different in straw incorporation rate. To verify the effects of depth and rate of straw incorporation on these factors： a field experiment was carried out in a tract of farmland of black soil. In the field experiment, corn stalk packed at a rate of 40 g kg-1 and 80 g kg-1 soil in nylon bags was buried into three soil layers different in depth （0-20, 20-40 and 40 - 60 cm ） for 4 years of in situ incubation for monitoring variations of corn stalk transformation, organic carbon accumulation, humus composition and soil enzyme activities. Results show that the addition of 40g kg-1 soil of the straw increased organic carbon by 31.8%, 96.4% and 171.1%, respectively, at the 0~20, 20 - 40 and 40 N 60 cm soil layers, and the addition of 80 g kg-1 soil of the straw did by 86.2%, 193.5% and 265.9 %, respectively; demonstrating that depth of the incorporation is conductive to soil organic carbon accumulation, because poor aeration in deep soil layers slows decomposition and transformation of the straw, thus favoring humus accumulation. However, in control （no straw incorporated ） , organic carbon declined by 29.3% in the 0 N 20 cm soil layer, but only by 1.8% in the 20-40 cm soil layer . The reason is that soil enzyme activity is higher in the shallow soil layer than in the deep soil layer, and hence, soil humus mineralization rate is much higher in the former than in the latter. Higher straw incorporation rate （ 80 g kg-1 soil

关 键 词：秸秆还田 土层 腐殖质积累特征 土壤酶活性 

分 类 号：S151.9[农业科学—土壤学]