不同有机物料对原生盐碱地水稳性团聚体特征的影响

为了研究不同种类和形态的有机物料对原生盐碱地水稳性团聚体特征以及物理性质的影响,以吉林西部地区原生盐碱地为研究对象,通过大田试验,分析了颗粒玉米秸秆、正常玉米秸秆、牧草以及羊粪等有机物料对原生盐碱地的浸水容重、沉降系数、田间持水量和蒸发速率等物理指标的影响,以及对土壤水稳性大团聚体和微团聚体的数量、形态、平均质量直径(MWD)、破坏率(PAD)、水稳系数、平均质量比表面积和分形维数等指标的影响。结果表明:(1)各处理中水稳性团聚体组成以微团聚体占主要成分,其中以0.05~0.25mm粒径为主,不同有机物料处理对各粒级含量影响差异显著。(2)各有机物料处理的土壤水稳性团聚体的稳定性相对CK处理均有所提高,羊粪处理对MWD提高效果最好,提高了104%,而颗粒处理提高水稳系数和降低PAD效果最好。(3)不同有机物料处理对水稳性团聚体形态均有改善作用,颗粒处理改善效果最好,形态圆润表面粗糙,大小孔径分布适中。(4)颗粒处理与其他处理的土壤团聚体分形维数差异显著,其他处理之间差异不显著,颗粒处理分形维数最低,相比CK处理降低了2.62%。各有机物料处理的平均质量比表面积与CK差异显著,其中正常秸秆处理最好,相比CK提高了171.01%。(5)各有机物料处理与CK处理相比,对原生盐碱土物理性质均有改善作用,颗粒处理整体效果最好。浸水容重与PAD和分形维数具有显著正相关性,与水稳系数和平均重量直径呈显著负相关性。沉降系数相关性类似浸水容重,田间持水量相反,蒸发速率则未显示出显著相关性,各物理参数与平均质量比表面积未显示出显著相关性。综合得出,有机物料能够改善原生盐碱土壤结构,同种有机物料不同形态作用效果不同,本试验中经过粉碎高温高压处理的颗粒秸秆效果远好于其他处理,有效地缩短了改良时间。

Effects of Different Organic Materials on the Characteristics of Water Stable Aggregates in a Primary Saline Alkali Soil

The study took the primary saline alkali land in the western of Jilin Province as the research object to investigate the effects of different types and forms of organic materials (granular corn straw,normal corn straw,grass,and sheep manure) on the physical properties and features of water stable aggregates in a primary saline soil by analyzing the immersion bulk density,sedimentation coefficient,field capacity,evaporation rate and quantity,form,failure rate (PAD),water stability coefficient,mean weight soil surface,mean weight diameter (MWD),fractal dimension of soil water stable macro-aggregates and micro-aggregates in the primary saline alkali soil treated with different organic materials in the experimental field.The results showed that:(1) The main components of water stable aggregates were micro-aggregates in each treatment,with the 0.05-0.25 mm micro-aggregates being dominant.The effects of different organic materials on the contents of aggregates of different sizes were significantly different.(2) The stability of soil water-stable aggregates treated with organic materials was better than that of CK.The optimum improvement in MWD was the sheep manure treatment,in which MWD was increased by 104％.The optimum improvement in water stability coefficient and the optimum reduction in PAD was the granular corn straw treatment.(3) The morphology of water stable aggregates was improved by all organic materials,with the granular corn straw treatment showing the best improvement effect,in which the shape of aggregates was round,the surface was rough,and the size distribution was moderate.(4) There were significant differences in fractal dimension of soil aggregates between the granular corn straw treatment and other treatments,but there was no significant difference among other treatments.The fractal dimension of the granular corn straw treatment was the lowest,being 2.62％ lower than that of CK.The average mass specific surface area of each organic material treatment was significantly different from that of CK,among which the normal corn straw treatment was the best,which increased the average mass specific surface area by 171.01％.(5) Compared to CK,each organic material treatment had a positive effect on the physical properties of the primary saline alkali soil.Immersion bulk density had a significant positive correlation with PAD and fractal dimension,and had a significant negative correlation with water stability coefficient and average weight diameter.The correlations for settlement coefficient were similar to those of immersion bulk density,but the correlations for field capacity were opposite.Evaporation rate did not show significant correlation,physical parameters and average mass specific surface area did not show significant correlation.In conclusion,organic materials could improve the primary structure of saline alkali soil,the same organic materials of different forms had different effects;in the present study,the granular corn straw treated with crushing,high temperature and pressure had better effects than other treatments and effectively shortened the improvement time.