作 者 ：刘震 徐明岗 段英华 张丽娟 张毅功
期 刊 ：植物营养与肥料学报 2013年 19卷 6期 页码：1386-1392
Keywords:long-term fertilization, nitrogen, black soil, red soil, soil aggregate,
摘 要 ：为阐明长期不同施肥下土壤氮库的演变特征，揭示氮库稳定性不同的团聚体对不同施肥的响应，为化肥和有机物的合理施用提供科学依据。本研究通过对黑土和红壤22年的田间肥料定位试验，研究了长期不同施肥模式对土壤全氮、 微生物氮以及各级团聚体中氮贡献率的影响。结果表明，长期不施肥（CK）和施用化肥（NPK），黑土土壤全氮含量以0.015 g/(kg·a)的速率显著下降（P< 0.05）；而长期化肥配施有机肥（NPKM），黑土全氮含量以0.025 g/(kg·a) 的速率显著上升（P< 0.05）。在CK、 NPK、 NPKM和秸秆还田（NPKS）处理下，红壤全氮含量均没有显著变化。施肥22年后，NPKM处理下黑土和红壤微生物氮含量较NPK处理下分别增加了15% 和 43%，全氮含量分别增加了43% 和45%，差异均达到显著水平（P< 0.05）。氮素在黑土上主要积累在253 μm 微团聚体中，达到0.73~1.21 g/kg，在红壤上主要积累在<2 μm 微团聚体中，达到0.46~0.98 g/kg。与NPK相比，NPKM 处理下黑土和红壤 250~2000 μm大团聚体中氮素贡献率均显著提高，分别增加了4.3% 和 5.1%。与NPK相比，NPKM 和 NPKS 处理下，红壤 253 μm 微团聚体中氮贡献率分别降低了5.9% 和 9.7%，而黑土除大团聚体外的各级团聚体氮贡献率均没有显著变化。可见，不同土壤类型对施肥响应不同, 主要是253 μm 微团聚体中氮素的响应不同，化肥配施有机肥可提高土壤250~2000 μm 大团聚体中氮的贡献率，进而增加土壤对作物的氮素供给能力，是有助于提高土壤肥力和生产力的农业生产可持续性施肥模式。
Abstract: In order to study the change dynamics of soil nitrogen and effect of long-term fertilization on N distribution in soil aggregates, the total nitrogen（TN）, soil microbial biomass nitrogen(SMBN) and nitrogen accumulation in four size aggregates were analyzed in black soils and red soils based on 22 year longterm fertilization experiments. The results show that the TN contents decrease at a rate of 0.015 g/(kg·a) for both the CK and the NPK treatments in black soil, while the contents increase at 0.025 g/(kg·a) for the NPKM treatment(P< 0.05). The TN contents of red soils do not changed significantly for all treatments over the fertilization period. Compared with the NPK treatment, the NPKM treatment increases SMBN by 15% and 43% and TN by 43% and 45% in black soils and red soils(P< 0.05), respectively. The highest nitrogen concentrations are detected in 2-53 μm microaggregates in black soils(0.73 -1.21 g/kg) and <2 μm microaggregates in red soils(0.46-0.98 g/kg) among the four sizes aggregates. Compared with the NPK treatment, the NPKM treatment results in 4.3 and 5.1 percentage increases for the ratio of N contribution in 250-2000 μm macroaggregates to total N, in black soils and red soils, respectively. The nitrogen contribution in 2-53 μm aggregates of red soils are significantly decreased by 5.9 and 9.7 percentages under the NPKM and NPKS treatments, respectively, compared with the NPK treatment. However, there is no significant change for the N contribution in black soils except 250-2000 μm macroaggregates. It suggests that it is 2-53 μm aggregates N which lead to different soil N amounts between the two soil types under the long-term fertilization. Combination of chemical fertilizer with manure improves the N distribution in 250-2000 μm macroaggregates, which has higher ability to apply N to crop than to microaggregates. Therefore, chemical fertilizer in combination with manure is a strongly recommended fertilization to improve soil fertility and develop sustainable agriculture.
全 文 ：