喷施秸秆颗粒和黏土混合浆形成结皮对科尔沁沙地固沙固碳的影响

Effects of spraying straw particles and clay mixed slurry to form crust on sand and carbon fixation in Horqin sandy land

为了寻求科尔沁沙地风积沙质土壤防风固沙,同时快速建置植被促进固沙效果,通过田间试验研究了喷施清水(CK)、喷施秸秆颗粒浆(PS)、喷施黏土浆(CM)、喷施秸秆颗粒与黏土混合浆(40%PS+60%CM)处理对沙质土壤结皮的形成与维持、有机碳含量及其组分、交换性阳离子和土壤团聚体组成的影响,并研究了狼尾草草籽加进秸秆颗粒与黏土混合浆对狼尾草生长状况的影响。结果表明,秸秆颗粒与黏土混合浆能形成良好的地表结皮并可维持一年的沙面稳定。试验第60 d时,与CK处理相比,40%PS+60%CM处理形成的混合结皮的土壤含水率提高了7.26%;结皮厚度较PS和CM处理增幅为44.00%~56.00%,土壤紧实度增幅为146.37%~283.16%。试验第300 d时,40%PS+60%CM处理较CK处理土壤有机碳含量显著提高了824.43%(P<0.05),并提高了腐殖质碳和胡敏酸碳含量;混合结皮和黏土结皮较CK处理显著增加了交换性钙离子含量(P<0.05),增幅为48.20%~120.66%;与CK相比,混合结皮显著提高了<53μm粒级团聚体比例(P<0.05),提高幅度为887.91%。冗余度分析表明,<53μm粉黏粒的比例是影响腐殖质碳和胡敏酸碳含量的重要因素。秸秆颗粒和黏土混合结皮对团聚体和阳离子的调节作用实现沙土中有机碳的积累。秸秆颗粒和黏土混合结皮的形成显著提高了狼尾草的地上部干重(P<0.05),提高幅度为315.38%~484.62%。综上,在科尔沁沙地喷洒秸秆颗粒和黏土矿物混合浆形成的结皮的维持时间较长,同时结皮增加沙质土壤中的有机碳和腐殖质含量,可减少风积沙土中细颗粒的损失,促进植物生长,达到有效固沙固碳的目的。

In order to seek the windbreak and sand fixation of aeolian sandy soil in Horqin sandy land,at the same time,quickly establish vegetation to promote sand fixation,field experiments were conducted to study the effects of spraying clear water(CK),straw granule slurry(PS),clay slurry(CM)and mixed slurry of straw granule and clay(40%PS+60%CM)on the formation and maintenance of sandy soil crust,organic carbon content and its components,exchangeable cations and soil aggregates,and the effects of Pennisetum grass seeds added with straw particles and clay mixed pulp on the growth of Pennisetum.The results showed that the crust formed by spraying straw particles and clay slurry on the surface of sandy soil within one year maintained the stability of sandy surface.On the 60th day,compared with CK treatment,the soil moisture content of mixed crust formed by 40%PS+60%CM treatment increased by 7.26%.Compared with PS and CM treatments,the crust thickness increased by 44.00%-56.00%,and the soil compactness increased by 146.37%-283.16%.On the 300^(th) day of the experiment,compared with CK,40%PS+60%CM treatment significantly increased the soil organic carbon content by 824.43%(P<0.05),and increased the contents of humus and humic acid.Compared with CK treatment,mixed crust and clay crust increased the exchangeable calcium ion content by 48.20%-120.66%.Compared with CK treatment,mixed crust increased the proportion of aggregates with particle size less than 53μm by 887.91%.Redundancy analysis showed that the proportion of clay particles smaller than 53μm was a vital factor affecting the content of humus and humic acid.The mixed crust of straw particles and clay regulated aggregates and cations to realize the accumulation of organic carbon in sandy soil.The formation of mixed crust of straw particles and clay increased the aboveground dry weight of Pennisetum by 315.38%-484.62%.To sum up,the crust formed by spraying the mixed slurry of straw particles and clay minerals in Horqin sandy land lasted for a long time,and at the same time,the crust increased the content of organic carbon and humus in sandy soil,which could reduce the loss of fine particles in aeolian sandy soil,promote plant growth and achieve the purpose of effectively fixing sand and carbon.