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试验研究了长期不同施肥下剖面(0~100 cm)土壤有机碳、全氮、硝态氮、微生物碳氮以及土壤pH的空间变化。结果表明:与单施化肥相比,长期有机肥和化肥配施显著提高了0~20 cm表层土壤有机碳、全氮、硝态氮和微生物碳氮含量,并且土壤有机碳和微生物碳氮的增加主要集中在0~40 cm土层。在0~20 cm和20~40 cm土层,等氮量有机无机肥配施(M1NPK和SNPK)处理土壤有机碳含量显著高于化肥NPK处理(P<0.05),同时二处理土壤全氮含量没有由于化肥氮施用量减少而下降。与不施肥ck相比,单施化肥显著降低了土壤微生物量碳氮含量。在40 cm土层以下,与NPK处理相比,M2NPK、NP和N处理硝态氮累积量明显增加,而M1NPK和SNPK处理硝态氮累积量明显减少。长期不同施肥对土壤酸化的影响主要集中在0~40 cm土层,单施化肥处理土壤pH显著低于不施肥(ck)和有机无机肥配施处理(P<0.05),其中2012年秸秆还田(SNPK)处理0~20 cm土壤pH比NPK处理高2.17。表明有机无机肥配施不仅能提高和维持土壤碳氮水平,还能防止土壤酸化的发生,尤其施用有机肥氮替代部分化肥氮的有机无机肥配施模式是东北黑土区最有效的施肥措施之一。
The spatial variations of soil organic carbon, total nitrogen, nitrate nitrogen, microbial carbon and nitrogen, and soil pH were studied under long-term fertilization (0-100 cm). The results showed that compared with the single application of chemical fertilizers, the application of long-term organic fertilizer and chemical fertilizer significantly increased the content of soil organic carbon, total nitrogen, nitrate nitrogen and microbial biomass nitrogen in 0-20 cm layer, and the contents of soil organic carbon and microbial carbon and nitrogen Increase mainly concentrated in 0 ~ 40 cm soil layer. In 0-20 cm soil layer and 20-40 cm soil layer, soil organic carbon content was significantly higher than that of NPK treatment (M1 <0.05) while the treatments of M1NPK and SNPK were the same, while the contents of total nitrogen No decline due to reduced fertilizer application of nitrogen. Compared with the non-fertilization ck, single application of chemical fertilizers significantly reduced soil microbial biomass carbon and nitrogen content. Under 40 cm soil layer, compared with NPK treatment, the accumulation of nitrate nitrogen by M2 NPK, NP and N significantly increased, while the accumulation of nitrate nitrogen by M1 NPK and SNPK decreased significantly. The effect of long-term different fertilization on soil acidification mainly concentrated in 0-40 cm soil layer. The pH of soil treated with chemical fertilizers was significantly lower than that of no-fertilization (ck) and organic-inorganic fertilizers (P <0.05) The soil pH of 0 ~ 20 cm in SNPK treatment was 2.17 higher than NPK treatment. It shows that the combination of organic and inorganic fertilizers can not only improve and maintain soil carbon and nitrogen levels, but also prevent soil acidification. In particular, organic and inorganic fertilizers that use organic fertilizers instead of some nitrogen fertilizers are the most effective fertilization measures in the black soil region of Northeast China one.