玉米秸秆全量深翻还田对高产田土壤结构的影响  

Effects of deep tillage and straw return on soil structure of high-yield spring maize field

作　　者：于博[1] 于晓芳[1] 高聚林[1] 胡树平[1] 孙继颖[1] 王志刚[1] 高鑫[1] 朱文新[1] YU Bo;YU Xiaofang;GAO Julin;HU Shuping;SUN Jiying;WANG Zhigang;GAO Xin;ZHU Wenxin(Inner Mongolia Agricultural University,Hohhot 010019,China)

机构地区：[1]内蒙古农业大学,呼和浩特010019

出　　处：《中国生态农业学报》2018年第4期584-592,共9页Chinese Journal of Eco-Agriculture

基　　金：国家玉米产业技术体系项目(CARS-02-63);国家科技支撑计划项目(2013BAD07B04);华北黄土高原地区作物栽培科学观测实验站基金(25204120);supported by the Maize Industrial Technology System Construction of Modem Agriculture of China(CARS-02-63);the National Key Technologies R&D Program of China(2013BAD07B04);the Fund of Crop Cultivation Scientific Observation Experimental Station in North China Loess Plateau(25204120);the National Key Research and Development Project of China(2017YFD0300804)

摘　　要：为达到玉米生产耕层最适深度(22 cm)和耕层最适土壤容重(1.1~1.3 g×cm^(-3)),解决内蒙古平原灌区耕层浅、犁底层坚硬且厚的农田土壤结构问题,分别选用连续1、2、3、4年秸秆深翻还田定位试验地,秋收后玉米秸秆全量粉碎深翻还田,秸秆年均还田量为20 034.97 kg×hm-2,形成秸秆深翻还田1~4年的4个试验处理(SF1-SF4),以不深翻秸秆还田的处理为对照(CK),研究土壤容重、土壤坚实度、土壤团聚体及其稳定性、土壤肥力及p H随不同年限秸秆深翻还田的变化规律。结果表明:1)SF1-SF4处理0~40 cm土层,土壤容重和土壤坚实度比CK显著减小。2)0~20 cm土层,SF4处理>0.25 mm团聚体比例(R0.25)、几何平均直径(GWD)和平均重量直径(MWD)均比CK显著减小;SF1处理土壤团聚体破坏率(PAD)比CK显著降低9.56%,不稳定指数(SWA)随深翻年限增加而显著降低;团聚体分形维数SF4比CK显著增大7.30%。3)20~40 cm土层,SF1和SF2处理R0.25比CK分别显著增加13.69%和17.83%;SF2处理的MWD和GWD分别比CK显著增加23.92%和53.38%;SF1-SF4处理的PAD比CK显著降低,且SF2显著高于SF1和SF3;而SF1-SF4的SWA比CK显著增加,且随秸秆深翻年限的增加呈逐渐升高趋势;团聚体分形维数SF2比CK显著降低7.39%。4)土壤有机质含量SF1-SF4比CK显著增加,且SF2-SF4处理显著大于SF1;速效氮、速效磷和速效钾SF1-SF4比CK显著增加,土壤p H SF3、SF4比CK显著降低。总之,深翻秸秆还田1~4年对0~40 cm土层土壤影响显著;深翻秸秆还田2年适合土壤犁底层结构的改良,深翻秸秆还田3年和4年适合土壤耕层结构的改良。玉米秸秆全量深翻还田既能达到耕作土壤的目的,同时也增加了土壤有机质,降低土壤团聚体破坏率和土壤水稳性团聚体的不稳定系数,利于培肥耕层土壤。There are some structural issues of farmland soils in the irrigated Inner Mongolia Plain,such as hard(bulk density of 1.55-1.62 g?cm-3),shallow plough layer(0–16 cm)and thick plow pan(45 cm).To solve these problems and achieve optimum tillage depth of 22 cm and soil bulk density of 1.1-1.3 g?cm-3 of the topsoil layer,a test with 1,2,3 and 4 years of continuous straw return plus deep tillage was conducted in a high-yield spring maize field in the Science-Technology Demonstration Garden of Inner Mongolia Agricultural University.The full maize straw(20 034.97 kg?hm-2)was crushed after autumn harvest and returned to soil combined with 40 cm deep tillage.Four treatments for 1-4 years of straw return plus deep tillage(SF1-SF4)were set and no deep tillage with maize straw return was the control(CK).The soil bulk density,hardness,aggregates and their stability,fertility and pH value were studied.The results showed that:1)in 0-40 cm layer,soil bulk density and hardness significantly decreased under SF1-SF4 treatments compared with CK.2)In 0-20 cm soil layer,the proportion of aggregates>0.25 mm(R0.25),mean weight diameter and geometric mean diameter of SF4 significantly dropped compared with CK.The percentage of aggregate disruption under SF1 significantly decreased by 9.56%compared with CK,the sabotage water-stable aggregates decreased significantly with years of the experiment.The fractal dimension of aggregates of SF4 significantly increased by 7.30%compared to CK.3)In 20-40 cm layer soil,the R0.25 of SF1 and SF2 were significantly increased by 13.69%and 17.83%,respectively,compared with CK;the mean weight diameter and geometric mean diameter of aggregates of SF2 were significantly increased by 23.92%and 53.38%.Then percentage of aggregate disruption of soil aggregates significantly decreased by 9.20%(SF1),3.02%(SF2),8.38%(SF3)and 3.16%(SF4)compared with CK.Sabotage water-stable aggregates significantly increased by 13.58%(SF1),16.49%(SF2),22.67%(SF3)and 25.42%(SF4)compared with CK.Fractal dimension of aggregates of S

关 键 词：春玉米 深翻 秸秆还田 土壤容重 土壤坚实度 土壤团聚体 分形维数 土壤养分 

分 类 号：S513[农业科学—作物学]