不同耕作方式下水稻田麦秸降解效果  

Decomposition of wheat stalk under different tillages in rice field

作　　者：王延鹏 汪小旵[1,2] 施印炎 魏天翔 杨四军 丁启朔[1] Wang Yanpeng;Wang Xiaochan;Shi Yinyan;Wei Tianxiang;Yang Sijun;Ding Qishuo(College of Engineering,Nanjing Agricultural University,Nanjing 210031,China;Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology&Equipment,Nanjing 210031,China;Institute of Agricultural Resources and Environment,Jiangsu Academy of Agricultural Sciences/Key Laboratory of Agricultural Environment in Lower Reaches of the Yangtze River,Ministry of Agriculture,Nanjing 210014,China)

机构地区：[1]南京农业大学工学院,南京210031 [2]江苏省现代设施农业技术与装备工程实验室,南京210031 [3]江苏省农业科学院农业资源与环境研究所/农业部长江下游平原农业环境重点实验室,南京210014

出　　处：《农业工程学报》2021年第15期239-247,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：江苏省农业科技自主创新资金(CX(17)1002)。

摘　　要：为研究稻麦轮作区不同耕作方式下水稻田麦秸的降解效果,在淮河中下游砂姜黑土区,试验测试了“耕翻+旋耕+泡田”(PRP)、“旋耕+泡田”(RP)、“泡田+旋耕”(PR)三种耕作方式下麦秸在45和90 d中的降解率、组分、养分残存量等参数变化情况,并在显微条件下观察了秸秆表面形态特征。结果表明:1)几种还田方式下,麦秸降解率都是先快后慢,到还田45 d时,其降解率达45%~55%,还田90 d时最高降解率也不超过58.27%。2)还田时间对麦秸碳(C)、氮(N)、磷(P)、钾(K),微观凹坑径向长度(L_(x))、微观凹坑轴向长度(L_(y)),力学强度有显著影响(P<0.05),对麦秸组分变化有影响。覆盖还田麦秸C、N、P、木质素、半纤维素随还田时间分别上升至其初始值的1.01~1.33、1.81~3.45、1.15~1.82、1.15~1.39、1.45~2.77倍,而麦秸K、纤维素则下降至其初始值的0.04~0.11、0.77~0.95倍;L_(x)和L_(y)随还田时间变化上升至其初始值的5.65~13.60、2.48~9.18倍;麦秸剪切、弯曲及压缩强度随还田时间下降至其初始值的0.07~0.34、0.26~0.58、0.43~0.76倍。3)耕作方式对覆盖还田麦秸N、P、K残存量影响显著(P<0.05),对组分变化有影响。PRP比RP、PR更能促进麦秸N、P、K、纤维素含量下降,提高木质素含量,而半纤维素随耕作方式变化无明显规律。因此,PRP是覆盖还田麦秸降解的较佳选择,其有助于还田麦秸力学强度下降,易引起秸秆表面崩解并形成微观凹坑,促进秸秆腐解及养分释放。Straw returning has widely been used in circular agriculture and soil conservation tillage in recent years.This study aims to explore the decomposition impacts of the wheat stalk under three tillage modes on the paddy filed in the summer rice and winter wheat system.A field experiment was conducted at the Shajiang black soil zone in the middle-lower reaches of Huaihe River.Three tillage treatments were set in the paddy filed,including“ploughing+rotary+puddling(PRP)”,“rotary+puddling(RP)”,and“puddling+rotary(PR)”.The decomposing parameters were then measured,such as the decomposing rates,the residual contents of the wheat stalk nutrients and components from 0 to 90 days(45 days as step length).A laser confocal scanning microscopy(OLS-4100,Olympus)was selected to characterize the microstructure of wheat stalk.The results showed that:1)The decomposition rate varied fast in the early stage,but slowly in the late stage.Specifically,the decomposition rate rapidly reached 45%-55%during 0-45 days,while the maximum value of the decomposition rate was less than 58.27%under different tillage and straw returning modes at 90 days.2)There were significant effects of returning time on the parameters,such as wheat stalk nutrients(including carbon(C),nitrogen(N),phosphorus(P),and potassium(K)),micro structures(including radial or X-direction length(L_(x)),axial or Y-direction length(L_(y))),and mechanical properties(including shearing strength(SS),bending strength(BS),compressive strength(CS))(P<0.05).The influence of returning time was found on the wheat stalk components(including Lignin(L),cellulose(Ce),Hemicellulose(He)).The residual contents of the wheat stalk components and nutrients such as C,N,P,L,and He increased to 1.01-1.33,1.81-3.45,1.15-1.82,1.15-1.39,1.45-2.77 times than those of the indexes at 0 day.Meanwhile the residual contents of the wheat stalk K and Ce decreased to 0.04-0.11,0.77-0.95 times than those of the indexes at 0 day.The Lx and Ly of micro-structure parameters were 5.65-13.60,2.48-9.18 time

关 键 词：降解 力学特性 耕作 麦秸还田 微观结构 

分 类 号：S210.3[农业科学—农业机械化工程]