长期不同施肥下黑土和红壤团聚体氮库分布特征  

Distribution of nitrogen in aggregates of black soil and red soil under long-term fertilization

作　　者：刘震[1,2] 徐明岗[2] 段英华[2] 张丽娟[1] 张毅功[1] 

机构地区：[1]河北农业大学资源与环境科学学院,河北保定071000 [2]农业部作物营养与施肥重点开放实验室,中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《植物营养与肥料学报》2013年第6期1386-1392,共7页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金项目(41001175);国家973项目(2011CB100501);农业行业专项(201203030)资助

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2 53μm微团聚体中,达到0.73 1.21 g/kg,在红壤上主要积累在<2μm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 2000μm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2 53μm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2 53μm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 2000μm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。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 long-term 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 250-2000μm 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 ferti

关 键 词：长期施肥 氮 黑土 红壤 团聚体 

分 类 号：S152.4[农业科学—土壤学] S158[农业科学—农业基础科学]