摘要
为了揭示不同坡度垄沟秸秆覆盖对团聚体形成和稳定性的影响,以吉林省伊通河青沟小流域农耕区为研究对象,通过设计3°,6°,9°3个坡面,沿着坡面进行顺坡耕作(无覆盖)与顺坡垄沟秸秆覆盖处理2种对比试验,分析了不同处理对土壤团聚体的数量、形态、平均质量直径(MWD)、平均几何直径(GMD)、破坏率(PAD)、水稳系数(K)和分形维数(D)等指标的影响。结果表明:垄沟秸秆覆盖与未覆盖相比,>0.25 mm的机械稳定性团聚体和水稳性团聚体的含量有所增加,变化趋势为9°>6°>3°。不同坡度处理的土壤团聚体的MWD和GMD值从大到小依次排序均为9°覆盖>3°覆盖>6°覆盖>9°无覆盖>6°无覆盖>3°无覆盖。分形维数均小于未覆盖,9°秸秆覆盖的分形维数最小,与9°未覆盖处理相比,降低了10.11%。9°覆盖处理的水稳系数最高。各坡度下土壤团聚体的结构破环率的排列顺序为3°无覆盖>3°覆盖>6°无覆盖>9°无覆盖>6°覆盖>9°覆盖。扫描电镜观察垄沟秸秆覆盖与未覆盖相比,各处理团聚体形态优劣均为9°>6°>3°,9°秸秆覆盖大多呈圆润多孔状,对团聚体改善效果最好。
In order to reveal the effects of furrow straw mulching of different slopes on the formation and stability of aggregates,taking the farming area of Qinggou small watershed in Yitong River of Jilin Province as research object,2 contrast treatments of ridge tillage along the slope and furrow straw mulching along the slope were carried out by designing three slopes of 3°,6°and 9°,and the effects of different treatments on number,morphology,mean weight diameter(MWD),geometric mean diameter(GMD),failure rate(PAD),water stability coefficient(K)and fractal dimension(D)of soil aggregates were analyzed.The results showed that:Compared with nocoverage treatment,the content of the mechanically stable aggregates and water-stable aggregates with>0.25 mm increased under furrow straw mulching treatment,and the change trend was 9°>6°>3°.In each slope treatment,MWD and GMD of furrow straw mulching were higher than those without coverage,and the order of MWD and GMD was 9°coverage>6°coverage>3°coverage>9°without coverage>6°without coverage>3°without coverage.The fractal dimension of 9°coverage was the lowest,10.11%lower than that of 9°without coverage.The water stability coefficient(K)of soil aggregates of 9°coverage was the highest.The order of PAD of soil aggregates under different slopes was:3°without coverage>3°coverage>6°without coverage>9°without coverage>6°coverage>9°coverage.Through scanning electron microscope observation,the shape and quality of each treatment were sorted as follows:9°>6°>3°.Most of the straw mulching of 9°was round and porous,and the best improvement effect on the aggregates was achieved.
作者
孙志旭
王宇
孙玲
刘健
王识然
张琪
SUN Zhixu;WANG Yu;SUN Ling;LIU Jian;WANG Shiran;ZHANG Qi(College of Resources and Environment,Jilin Agricultural University,Key Laboratory of Sustainable Utilization of Soil Resources in the Commodity Grain Bases in Jilin Province,Changchun 130118,China)
出处
《吉林农业大学学报》
CAS
CSCD
北大核心
2020年第1期84-89,共6页
Journal of Jilin Agricultural University
基金
国家重点研发计划项目(2017YFC0504200)
松辽流域全国水土流失动态监测与公告项目(126205012000150001)。
