【摘要】 以连续5a设施番茄栽培定位施肥田间试验为依托,选择施氮量0、187.5、375.0、562.5kg·hm^-2（N0、N1、N2、N3）及氮肥与有机肥(M:75000kg·hm^-2)配施（MN0、MN1、MN2、 MN3） 8个处理,研究了不同施氮及氮肥与有机肥配施处理土壤总有机碳（Total organic carbon,TOC）和水溶性有机碳（Water soluble organic carbon,WSOC）的含量及其剖面分布,土壤松/稳结态胡敏酸碳（Humic acid carbon,HA-C）和富里酸碳（Fulvic acid carbon,FA-C）含量、组成及其剖面分布。结果表明:各施肥处理TOC、WSOC、稳结态胡敏酸碳（HA₂-C）和稳结态富里酸碳（FA₂-C）含量均随土层深度增加呈逐渐下降趋势,而松结态胡敏酸碳（HA1-C）和松结态富里酸碳（FA₁-C）含量均随土层深度增加呈先增加后逐渐下降趋势。与单施氮肥处理相比,氮肥与有机肥配施处理均使0～50 cm土壤TOC、WSOC、HA₁-C、FA₁-C和HA₂-C含量有所提高,其提高幅度分别为12.44%～87.38%、11.01%～168.32%、10.15%～235.54%、2.41%～205.21%和3.42%～92.61%;同时也显著提高了0～20 cm土层HA/FA及PQ（HA占（HA+FA）的比例）（P <0.05）,使0～20 cm土层HA₁、HA₂和FA₁的C/N比增加,FA₂的C/N比略有下降,HA的E₄/E₆（在波长为465nm和665nm处吸光度的比值）降低,FA的E₄/E₆增加。本设施番茄栽培田间试验条件下,连续5 a氮肥与有机肥配施不仅显著提高了0～20 cm土壤有机碳数量,而且有利于FA向HA转化,促进胡敏酸的形成与累积,尤其是松结态胡敏酸的形成与累积,进而使土壤有机碳品质得到明显改善。更多还原

【Abstract】 【Objective】 Composition and component ratio of soil humus are important indicators for assessing soil organic carbon quality, and also have important influences on soil structure and quality. Soil humus varies in combination form and hence in effect on soil structure and soil fertility as well. Therefore,it is of great significance to rational fertilization in facilitated vegetable production to study effect of application of nitrogen（N） fertilizer and organic manure on component contents, composition and profile distribution of soil humus under greenhouse.【Method】For this study a field fertilization experiment was conducted in a greenhouse growing tomato for five consecutive years. The experiment was designed to have four treatments（N0, N1, N2 and N3） of applying merely N fertilizer at a rate of 0, 187.5, 375.0, and562.5 kg·hm^-2, respectively, and four（MN0, MN1, MN2 and MN3） combined application of N fertilizer and organic manure that is, each of the four N treatments coupled with organic manure(M: 75 000 kg·hm^-2).Total organic carbon（TOC）, water soluble organic carbon（WSOC）, soil loosely and stably combined humic acid carbon（HA-C） and fulvic acid carbon（FA-C） in all the eight treatments were monitored for content, composition and profile distribution in the greenhouse soil. Soil water soluble substance（WSS）,loosely combined humus and stably combined humus were extracted with Fu Jiping, soil humic acid（HA）and fulvic acid（FA） separated with the modified humus component method, and organic carbon content of each determined. 【Result】 In all fertilization treatments, the contents of TOC, WSOC, stably combined humic acid carbon（HA2-C） and fulvic acid carbon（FA2-C） gradually decreased with soil depth, whereas the contents of loosely combined humic acid carbon（HA1-C） and fulvic acid carbon（FA1-C） increased first and then decreased with soil depth. But the contents of soil TOC, WSOC and humus components were the highest in the 0～20 cm soil layer. Compared with application of mere N fertilizer, combined fertilization increased the content of TOC, WSOC, HA₁-C, FA₁-C and HA₂-C by 12.44%～87.38%, 11.01%～168.32%,10.15%～235.54%, 2.41%～205.21% and 3.42%～92.61%, respectively, in the 0～50 cm soil layer. The effect was especially significant for TOC, WSOC, HA₁-C, FA₁-C and HA₂-C in the 0～20 cm soil layer（P <0.05） and for HA1-C, FA1-C and HA₂-C in the 40～50 cm soil layer（P < 0.05）. Combined fertilization also significantly improved the ratio of HA1/FA₁, HA₂/FA₂, and HA/FA and PQ1（HA₁-C/（HA₁-C+ FA₁-C））, PQ₂（HA₂-C/（HA₂-C+ FA₂-C））, and PQ（HA-C/（HA-C+ FA-C）） in the 0～20 cm soil layer（P < 0.05）, increased the C/N ratios of HA₁, HA₂ and FA1, but slightly decreased that of FA₂ in the 0～20 cm soil layer. Besides,combined fertilization also decreased E₄/E₆（The ratio of absorbance at 465 nm and 665 nm wavelengths） of the soil HA, but increased E₄/E₆ of the soil FA.【Conclusion】 Under the conditions of tomato cultivation in the greenhouse, combined fertilization for 5 consecutive years not only significantly increases the amount of soil organic carbon in the 0～20 cm soil layer, but also helps FA transform to HA, promotes formation and accumulation of humic acid, especially loosely combined humic acid, and consequently improves quality of the soil organic carbon significantly. It is, therefore, concluded that combined application of 187.5 kg·hm^-2 N fertilizer and 75 000 kg·hm^-2 organic manure is the best option to improve quantity and quality of soil organic carbon.更多还原