摘要
采用裂区试验设计方法,以铁尾矿砂为生长基质进行紫花苜蓿(Medicago sativa L.)盆栽试验,探讨了紫花苜蓿接种不同根瘤菌菌株和施肥水平对紫花苜蓿生长的影响,以筛选出明显促进紫花苜蓿生长的根瘤菌菌株与施肥水平的最佳组合。在最佳组合条件下,研究了紫花苜蓿连续种植2a后铁尾矿基质理化性质和生物学特性的变化。结果表明:(1)接种根瘤菌明显促进了紫花苜蓿根瘤重、根鲜重、地上部鲜重、株高的提高,其中以接种菌株17676的效果明显。(2)施肥对紫花苜蓿的生长有显著的促进作用。随着施肥水平的提高,紫花苜蓿的各项生长指标均逐渐增大,在5%施肥水平时最高,并且在5%施肥水平时紫花苜蓿地上部鲜重和株高与2.5%和1%2个施肥水平间差异显著。2.5%施肥水平下,紫花苜蓿根瘤重最大,但与5%施肥水平差异不显著。表明5%施肥水平对促进紫花苜蓿生长的效果最佳。(3)与对照(裸尾矿砂)相比,在5%施肥水平条件下,种植接种17676菌株的紫花苜蓿后,铁尾矿砂基质的理化性质和生物学特性均有了极为明显的改善(P<0.01)。其中,容重显著下降,田间持水量和总孔隙度明显提高,pH值显著下降并接近中性,有机质和速效养分(碱解氮、速效磷、速效钾)含量显著提高,基质中的细菌、真菌和放线菌的数量以及土壤酶(过氧化氢酶、脲酶、蔗糖酶、磷酸酶和纤维素酶)活性明显提高。(4)与播种当年相比,种植紫花苜蓿2a的铁尾矿砂基质的理化性质和生物学特性均有不同程度的改善。其中,除了细菌和真菌数量以及有机质和碱解氮含量的提高效果不明显外,其他各项指标均达到了显著水平。表明5%有机肥水平条件下种植接种17676菌株的紫花苜蓿对铁尾矿砂基质的改良效果显著,紫花苜蓿种植年限对铁尾矿砂基质的改良效果也有重要作用。
In this paper,the iron tailings was used as growth substrate to investigate the effect of Medicago sativa L.inoculated with different rhizobium strains and fertilization levels on the Medicago sativa L.growth by a pot experiment using split-plot experiment design,in order to screen out the best combination of rhizobium strain and fertilization level for Medicago sativa L.growth.The changes of the physical and chemical properties and biological characteristics of the iron tailing substrate were studied,after 2years of Medicago sativa L.planting under the condition of the optimum combination of rhizobium strain and fertilization level.The results showed that：（1）rhizobium inoculation significantly promoted the fresh weights of root nodule,root and aboveground plant of Medicago sativa L.,and plant height.The ameliorative effect was the most significant when 17676 rhizobium strains were inoculated.（2）Fertilization significantly promoted Medicago sativa L.growth.With the increasing fertilization level,the growth indices of Medicago sativa L.increased gradually,and reached maximum at fertilization level of 5%.Moreover,the height and fresh weight of aboveground plant ofMedicago sativa L.at fertilization level of 5% were significantly different with those at fertilization levels of2.5% and 1%.At the fertilization level of 2.5%,the root nodule weight of Medicago sativa L.was the highest,but it did not significantly differ with that at the fertilization level of 5%,indicating that the effect of 5%fertilization level on Medicago sativa L.growth was the best.（3）The physicochemical properties and biological characteristics of iron tailing substrate were improved significantly,after 1year of Medicago sativa L.growth with the inoculation of 17676 rhizobium strains under the condition of 5%fertilization level,compared with those in the control treatment（bare tailings）（p〈0.01）.The bulk density of iron tailing substrate decreased significantly,while the field water capacity and total porosity increased significantly,pH decreased significantly to the near neutral level,the contents of organic matter and available nutrients（available nitrogen,available phosphorus and available potassium）greatly increased,and the quantity of bacteria,fungi and actinomycetes,as well as soil enzymatic activities（catalase,urease,sucrase,phosphatase and cellulose）,in iron tailing substrate increased significantly.（4）Compared with the physical and chemical properties and biological characteristics of the iron tailing with 1year of Medicago sativa L.planting,those of iron tailing substrate with 2years of Medicago sativa L.planting were improved to different extents under the condition of optimum combination of fertilization level and rhizobium strain inoculation.Except the quantity of bacteria and fungi,and the contents of organic matter and available nitrogen,the other indices were significantly increased.It showed that the ameliorative effects of Medicago sativa L.inoculated with 17676 rhizobium strains at the fertilization level of 5% on the iron tailing substrate were significant,and the growth year of Medicago sativa L.also played an important role in influencing ameliorative effects of Medicago sativa L.on iron tailings.
出处
《水土保持学报》
CSCD
北大核心
2016年第1期272-277,共6页
Journal of Soil and Water Conservation
基金
"十二五"环境领域国家科技计划项目(2012BAC09B03)
"十二五"农村领域国家科技计划项目(2011BAD38B0103-3)
关键词
紫花苜蓿
根瘤菌
施肥
铁尾矿
改良效果
Medicago sativa L.
rhizobium
fertilization
iron tailings
ameliorative effects
