不同施肥措施对白土腐殖质组成的影响

以白土稻区4年大田定位试验为基础,设置2种翻耕深度(10 cm、20 cm,分别标记为T10、T20)和4种施肥措施(单施化肥、化肥+畜禽粪肥、化肥+秸秆还田、化肥+绿肥,分别标记为F、F+M、F+S、F+G),通过腐殖质组成修改法分别提取表层土壤水溶性物质、胡敏酸、富里酸和胡敏素,研究不同施肥措施对白土腐殖质各组分碳含量的影响。结果表明:单施化肥措施下,翻耕20 cm处理(T20+F)土壤总有机碳和腐殖质各组分碳含量均低于翻耕10 cm处理(T10+F),但差异未达显著水平。在翻耕20 cm的基础上增施有机肥能显著提高土壤总有机碳和腐殖质各组分碳含量,增施畜禽粪(T20+F+M)、秸秆还田(T20+F+S)和增施绿肥(T20+F+G)3处理的土壤总有机碳、胡敏酸、富里酸和水溶性物质碳含量较T20+F处理分别提高14.57%~30.64%、10.36%~30.57%、0.74%~12.31%和14.25%~26.80%。增施有机肥显著提高胡敏素碳含量,T20+F+M、T20+F+S和T20+F+G处理较T20+F处理提高18.87%~35.78%。4年不同翻耕与施肥措施对白土腐殖质性质未产生显著影响。增施有机肥能一定程度上提高土壤PQ值、胡富比、E4/E6值和色调系数。相关性分析表明,胡敏素、胡敏酸、富里酸碳含量与总有机碳含量间均存在显著或极显著正相关,与水溶性物质碳含量间无明显相关性。

Effects of Different Fertilizations on Humus Components of White Soil

A four-year field experiment was carried out in paddy field at white soil to study the effects of different fertilizations on carbon contents of soil humus components. The treatments consisted of two tillage depths of 10 cm and 20 cm (T10, T20) and four fertilizations of chemical fertilizer (F), chemical fertilizer and farmyard manure (F+M), chemical fertilizer and wheat straw (F+S), chemical fertilizer and green manure (F+G). The water-soluble substance, humic acid, fulvic acid and humic material of white soil were extracted using composition method. The results showed that carbon contents in bulk soil and humic substances in T20+F treatment were lower than in T10+F treatment. The addition of organic manure with the tillage depth of 20 cm significantly increased the contents of total organic carbon and humus components. Compared with T20+F treatment, total organic carbon and organic carbon contents of humic acid, fulvic acid and water-soluble substance in T20+F+M, T20+F+S and T20+F+G treatments were increased by 14.57%–30.64%, 10.36%–30.57%, 0.74%–12.31% and 14.25%–26.80%, respectively. The addition of organic manure significantly increased organic carbon contents of humic material by 18.87%–35.78% in T20+F+M, T20+F+S and T20+F+G treatments, compared with T20+F treatment. Different tillage depths and fertilizations showed no significant effect on humus properties. The addition of organic manure increased PQ values, HA/FA ratio, E4/E6values andΔlogK to a certain extent. Correlation analysis showed significant or extremely significant positive correlations existed among humic material, humic acid, fulvic acid and total organic carbon, while no correlation with water-soluble substance.