【摘要】 针对吉林省黑土区存在的土壤有机质下降、耕地质量退化等问题,利用公主岭国家黑土肥力与肥料效益监测基地连续20年的长期定位试验,采用核磁共振波谱分析法(NMR)、红外光谱分析法(IR)等现代分析方法,研究了不同培肥途径耕层土壤腐殖质的组成、形态结构及动态变化趋势。结果表明:不同培肥途径对耕层土壤腐殖质特征影响明显。施用玉米秸秆处理(S+NPK)和施用有机肥+轮作处理(M+NPK+R)均显著增加了土壤胡敏酸中脂肪族结构成分,单施有机肥处理(M+NPK)显著增加了土壤胡敏酸中羟基含量,S+NPK处理游离羧基含量显著增多。S+NPK、M+NPK及M+NPK+R处理,土壤富啡酸的甲基、亚甲基和次甲基结构成分显著增多,游离羧基含量也显著增多。单施化肥处理,浸提的富啡酸中无机碳酸盐和硅酸盐成分明显增多,化肥长期施用导致土壤中游离富啡酸数量显著减少,土壤的耗竭式利用,导致土壤中铁、铜结合态或络合态的富啡酸增加。不同培肥方式对黑土胡敏酸和富啡酸的元素组成影响有较大的差异,但均可引发胡敏酸C含量降低,N含量增加,富啡酸C、N、H含量增加,O含量降低,可通过不同的培肥方式对土壤腐殖质的元素组成进行调节。更多还原

【Abstract】 To tackle the problems,such as declining soil organic matter content and degrading farmland quality in the black soil region of Jilin Province,soil samples were collected from a 20-year long-term stationary field experiment on fertilization at the Gongzhuling National Black Soil Fertility and Fertilization Efficiency Monitoring Base for analysis of composition and morphological structure of soil humus by means of modern analytical methods,like NMR Spectroscopy and IR Spectroscopy and exploration of their dynamic variation as affected by fertilization method. It was found that fertilization methods had some significant effects on characteristics of soil humus in cultivated layers. In the field experiment,the component of aliphatic structure in soil humic acid( HA) increased significantly in Treatment S + NPK( conventional NPK plus incorporation of corn stalks) and Treatment M + NPK + R( conventional NPK plus organic manure and crop rotation;the content of oxhydryl in soil HA increased obviously in Treatment M + NPK( conventional NPK plus organic manure)the content of free carboxyl increased too in Treatment S + NPK; the component of methyl,methylene and methenyl structures in fulvic acid( FA) increased obviously and free carboxyl did too in Treatments S + NPK,M + NPK and M + NPK +R; and inorganic carbonate and silicate increased in the FAs exacted from the soil of Treatment NPK,which means longterm application of chemical fertilizer may cause reduction of free FAs and exhaustive utilization of soil may lead to increase in FA of iron-and copper-bounded or complexed form. Obviously,fertilization methods vary in effect on elemental composition of HA and FA in black soil,and nevertheless all of them reduce HA C content and increase HA N content and FA C,FA N and FA H contents and reduce FA O content. Treatments F( fallow) and M + NPK + R increased soil HA N content the most significantly,while Treatments F and S + NPK reduced soil HA C content the most significantly. Compared with CK,Treatment F reduced soil HA H content markedly,while all the other treatments increased the content markedly. F fertilization,regardless of method,reduced of oxidation degree of soil FAs. Obviously Treatments F,M +NPK + R,M + NPK were better than treatment NPK in adjusting C,H,O and N components in soil FAs. It is,therefore,concluded that elemental composition of soil humus can be regulated by using different fertilization methods.更多还原