施用有机物料对宁夏沙化土壤碳氮及微生物特性的影响

发布时间：2018-05-02 07:53

本文选题：有机物料 + 沙化土壤　；参考：《宁夏大学》2017年硕士论文

【摘要】：为探讨施用有机物料对宁夏沙化土壤的改良效果,以当地易得的杨树枝条、玉米秸秆、牛粪为原料,通过桶栽方法研究了有机物料单施和配施对宁夏沙化土壤碳氮及微生物特性的影响。本研究共设7个处理:(1)无任何有机物添加的对照(CK);(2)土壤单施3%牛粪(CM);(3)土壤单施3%杨树枝条(PB);(4)土壤单施3%玉米秸秆(CS);(5)土壤配施1.5%杨树枝条+1.5%牛粪(PB+CM);(6)土壤配施1.5%杨树枝条+1.5%玉米秸秆(PB+CS);(7)土壤配施1.5%玉米秸秆+1.5%牛粪(CS+CM);(8)土壤配施1%杨树枝条+1%玉米秸秆+1%牛粪(PB+CS+CM)。有机物添加量为土壤质量比,每桶施尿素(CH4N20)5g,磷酸二氢钾(KH2P04)2 g。每个处理4个重复/桶,共计32个试验桶。主要研究结果如下:(1)矿化实验结果表明,有机物料在土壤中的分解速率受到土壤碳氮含量及有机物料本身碳氮含量的影响,有机碳氮矿化速率先快后慢。在培养的前期,有机物料分解速率依次为:CSPBCM,在培养后期依次为:PBCSCM。向土壤中施加杨树枝条对提高土壤有机碳含量的效果最佳,而向土壤中施加牛粪则对土壤有机氮含量的提高效果最佳。因此,配施有机物料可能会为土壤提供持续的碳源和氮源,更有利于植物的生长。(2)2015-2016年的桶装模拟试验结果表明,在沙化土壤施加有机物料均使土壤除无机氮外的其它不同碳氮组分含量有不同程度的增加。单施牛粪处理不仅可以有效增加土壤的无机氮,而且与对照和其它处理相比土壤有机碳、易氧化有机碳、全氮和水解氮含量较均最高,但出现抑制紫花苜蓿生长的现象;而杨树枝条+玉米秸秆+牛粪的配施处理对提高土壤微生物生物量碳和氮含量的效果最佳,同时对土壤酶活性的提高也表现出最佳的趋势,该处理下紫花苜蓿生物量在所有处理间也最高。(3)对土壤微生物功能多样性的研究表明,施用有机物料使土壤微生物利用碳源总量增加,微生物代谢活性增强,土壤有机碳含量和土壤肥力水平也可能随之提高。其中单施杨树枝条对土壤微生物代谢的促进作用最强。对细菌群落结构的研究表明沙化土壤施用杨树枝条可以促进Proteobacteria(变形菌门)细菌数量的增加,施加玉米秸秆可以促进Ascomycota(子囊菌门)真菌数量的增加。综上所述,有机物料是改良宁夏沙化土壤的良好材料,特别确定出宁夏最常见的杨树枝条改良沙化土壤理论可行性:土壤施入杨树枝条后促进土壤微生物利用碳源总量增加,还可以提高Proteobacteria(变形菌门)细菌的数量。杨树枝条+玉米秸秆+牛粪的配施处理对提高土壤微生物生物量碳氮含量及酶活性的效果最佳,该处理下紫花苜蓿生物量在所有处理间也最高。单施牛粪处理不仅可以有效增加土壤的无机氮,而且与对照和其它处理相比土壤有机碳、易氧化有机碳、全氮和水解氮含量较均最高,但出现抑制紫花苜蓿生长的现象。施加玉米秸秆可以促进Ascomycota(子囊菌门)真菌数量的增加。需要注意的是,施用有机物料均可造成土壤碳氮失衡,引起微生物固持碳素,需在施用时调节土壤碳氮比。
[Abstract]:The results were as follows : ( 1 ) The decomposition rate of organic material in the soil was 1 . 5 % corn stalk + 1 % cattle manure ( PB + CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; ( 5 ) the soil was applied with 1.5 % poplar branch + 1.5 % corn stalk ( CS + CM ) ; and ( 5 ) the organic material may provide continuous carbon source and nitrogen source to the soil , thereby facilitating the growth of the plant . ( 2 ) In 2015 - 2016 , the results showed that the contents of soil organic carbon , organic carbon , total nitrogen and hydrolyzed nitrogen were the best among all treatments .

【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154.3;S153

【参考文献】