摘要
为探讨化肥有机肥配施对黑土团聚体稳定性及其富里酸结构的影响,依托中国科学院海伦农业生态试验站2001年设置的长期定位试验,分析不施肥(CK)、单施化肥(NPK)、化肥+15000 kg·hm-2有机肥(NPKM1)及化肥+22500 kg·hm-2有机肥(NPKM2)处理对土壤团聚体稳定性、团聚体富里酸结构及光学特性的影响.结果表明:(1)化肥有机肥配施显著提高了0～40 cm土层>0.25 mm团聚体分布比例,增强了土壤团聚体稳定性;与CK相比,NPKM1和NPKM2处理的0～20 cm土层>0.25 mm团聚体分布比例分别增加6.2%～26.3%和8.4%～50.2%.(2)土壤各粒径团聚体富里酸包含类富里酸、类胡敏酸和类蛋白质共3种荧光组分,化肥有机肥配施提高了类富里酸、类胡敏酸组分荧光强度及百分比和类蛋白质组分荧光强度,降低了类蛋白质组分荧光强度百分比;与CK相比,NPKM1和NPKM2处理>0.25 mm团聚体富里酸的类富里酸和类胡敏酸组分荧光强度分别提高7.0%～30.5%和12.8%～45.4%.同时土壤各粒径团聚体富里酸均受自生源和外生源共同作用的影响(FI(荧光指数)>1.4,0.8<BIX(自生源系数)<1.0),呈现强腐殖化和新近自生源特征(3.0<HIX(腐殖化指数)<6.0).(3)土壤各粒径团聚体富里酸的SU-VA254、SUVA280和E4/E6值随有机肥施用量增加而增加,芳香性增强,分子结构变简单.相关性分析表明,土壤团聚体富里酸荧光组分、芳香性(SUVA254)、腐殖化程度(HIX、E4/E6)是影响团聚体稳定性的重要因素.因此,化肥有机肥配施通过增加团聚体富里酸荧光组分强度,提高团聚体芳香性和腐殖化程度,进而提高土壤团聚体稳定性.
Abstract
To investigate the effects of chemical fertilizer combined with organic manure on the distribution and fulvic acid structure of soil aggregates,a long-term positioning experiment was established in Hailun Agroecosystem Experimental Station,Chinese Academy of Science in 2001,including four treatments of no fertilizer ( CK),single chemical fertilizer ( NPK ),chemical fertilizer+15000 kg·hm-2 organic manure ( NPKM1 ),and chemical fertilizer+22500 kg·hm-2organic manure (NPKM2).The results showed that:(1) The combined application of chemical and organic fertilizers significantly increased the proportion of>0.25 mm soil aggregates in the 0～40 cm soil layer,thereby enhancing the stability of soil aggregates.Compared with the CK treatment,the proportions of>0.25 mm aggregates in the 0～20 cm soil layer increased by 6.2%～26.3%,and 8.4%～50.2% under the NPKM1,and NPKM2 treatments,respectively.(2) The fulvic acid in soil aggregates of various particle sizes contains three fluorescent components:fulvic acid-like,humic acid-like,and protein-like substances.The combined application of chemical and organic fertilizers increased the fluorescence intensity and percentage of fulvic acid-like,humic acid-like components and the fluorescence intensity of the protein-like component in the soil aggregates,while re-ducing the percentage of protein-like component fluorescence intensity.Compared with the CK,the fluorescence in-tensities of fulvic acid-like and humic acid-like components in the>0.25 mm aggregates increased by 7.0%～30.5%,and 12.8%～45.4% under the NPKM1,and NPKM2,respectively.Additionally,the fulvic acid in soil ag-gregates of various particle sizes was influenced by both autochthonous and allochthonous sources ( with a fluores-cence index ( FI)>1.4,and a biological index ( BIX) between 0.8 and 1.0),showing strong humification and re-cent autochthonous characteristics (with a humification index (HIX) between 3.0 and 6.0).(3) The values of SU-VA254,SUVA280,and E4/E6 of fulvic acid in each soil aggregate size showed an increasing trend as the increase of organic manure,increased aromaticity and simplified molecular structure.Correlation analysis shows that the fluo-rescence components of fulvic acid (fulvic acid-like,humic acid-like and protein-like),aromaticity (SUVA254) and humification degree ( HIX,E4/E6) were important factors affecting the stability of soil aggregates.Therefore,the combined application of chemical fertilizer and organic fertilizer increased the intensity of fulvic acid fluores-cence components of soil aggregates,improved the aromaticity and the degree of humification of soil aggregates as well as the stability of soil aggregates.
基金项目
国家重点研发计划(2022YFD1500100)
中国科学院战略性先导科技专项A类(XDA28070100)
现代农业产业技术体系(CARS-04)
维普
万方数据