长期施肥下不同有机质含量的农田黑土水稳性团聚体中氮、磷的分布特征

Spatial Distribution of Water-stable Aggregates N and P Under the Long-term Fertilization in the Different Organic Matter Contents of Farmland Black Soil

研究长期施肥对不同有机质含量农田黑土水稳性团聚体分级特征、不同粒级团聚体中全氮、全磷含量分布及相关性的影响，为阐明施肥对黑土肥力演变的影响机制提供理论依据。利用中国科学院海伦生态实验站空间移位长期定位试验，研究2种施肥方式下5种不同有机质含量的农田黑土不同粒级水稳性团聚体、水稳性团聚体中全氮、全磷分布特征。结果表明：长期施用化肥对2-1mm粒级大团聚体含量影响最大，施肥处理在该粒级团聚体分别增加了1．95％-4．59％之间，且各粒级水稳性团聚体随土壤有机质含量的增加而呈递增的趋势。不同农田黑土全氮、全磷在2～1mm粒级大团聚体中含量最高，在〉5mm和〈0．25mm含量最低。2～0．5mm土壤团聚体含量与土壤全氮、全磷存在显著的正相关关系，〉5mm和〈0．25mm与土壤全氮、全磷存在显著负相关关系。土壤全氮、全磷主要存在水稳性大团聚体中，施用化肥可提高水稳性大团聚体中全氮、全磷的含量，是改善农田黑土土壤结构，提高土壤肥力的有效措施。

Based on long-term soil removal method in Hailun ecological station, Chinese Academy of Science, it was studied for water-stable aggregate fractions, total N and total P in various aggregates fractions and their relationship under the long-term fertilization in the different organic matter of farmland black soil. The research helps to provide theoretical basis for influence mechanism of fertilization on the changes of black soil fertility. The results showed that the long-term chemical fertilization made the most important effect on macroaggregates fractions （2-1 mm）, and its content increased by 1.94%-4.59%. Various aggregates fractions increased gradually with soil organic matter increasing. For different farmland black soils, the contents of total N and total P is the highest in macroaggregate fractions （2-1 mm）, and the lowest in aggregate fractions （〉5 mm, 〈0.25 mm）. Soil aggregates （2-0.5 mm） had positive relationship with total N and total P, but soil aggregates （〉5 mm, 〈0.25 mm） were significantly negative correlation with them. Soil total N and total P mainly existed in maeroaggregates. The used chemical fertilizer might increase the content of total N and total P in water-stable aggregates, which is the effective measure for improving soil structure of farmland black soil and increasing soil fertility.