不同施肥模式对砂姜黑土团聚体特征及有机碳的影响

采集32年砂姜黑土长期定位试验不施肥(CK)、单施化肥(NPK)、单施有机肥(M)、有机肥与化肥配施(MNPK)和高量氮肥下有机肥与化肥配施(HMNPK)处理耕层土壤,研究砂姜黑土区麦玉轮作系统中总有机碳、团聚体组成及不同粒径团聚体中有机碳含量对长期不同施肥模式的响应。结果表明,长期不同施肥方式显著影响土壤不同粒径团聚体分布及其有机碳含量。有机肥施用对表层土(0—10 cm)1—0. 5 mm、0.5—0.25 mm干筛团聚体和< 0.25 mm微团聚体含量的提高有促进作用。耕层土壤水稳性团聚体主要分布在1—0.5 mm、0.5—0.25 mm和<0.25 mm粒径中,施肥处理对各粒级水稳性团聚体含量没有显著影响。长期施肥显著提高了表层土1—0.5 mm和0.5—0.25 mm干筛中团聚体有机碳含量,HMNPK的增幅最高。施用有机肥对提高土壤水稳性团聚体有机碳含量有积极作用,尤其对1—0.5 mm、0.5—0.25 mm和<0.25 mm粒径水稳性团聚体有机碳含量的提高有显著影响,且均为M处理提高幅度最大。砂姜黑土区麦玉轮作条件下,长期有机肥施用可提高砂姜黑土土壤总有机碳含量、中团聚体数量以及有机碳含量,有利于改善土壤物理性状、提升地力。

Effects of Fertilization Patterns on Lime Concretion Black Soil Aggregate Characteristics and Organic Carbon

The influences of different long-term fertilization patterns on the lime concretion black soil aggregate composition and organic carbon distribution were studied, to provide scientific basis for eliminating bad attributes in soils and establishing rational fertilization system in this area. Based on long-term fertilization experiment in Yangliu village of Anhui province, soil samples were collected at different soil depths. The experiment included five treatments: non-fertilization (CK), application of single chemical fertilizer (NPK), application of single organic fertilizer (M), mixed application of organic and chemical fertilizer with the same amount of nitrogen (MNPK), mixed application of organic and chemical fertilizer with the larger amount of nitrogen (HMNPK). Grading the soil aggregate structure by dry sieving and wet sieving method, and total organic carbon in soils and organic carbon in different size aggregates were determined. The results showed that long term fertilizations significantly affected the distribution of different fractions size aggregates and their organic carbon contents. Organic fertilizer application increased the amount of size 1-0.5 mm, 0.5-0.25 mm macro-aggregate and < 0.25 mm micro-aggregate amounts at 0-10 cm soil layer. The water stable aggregates in the topsoil are mainly distributed in 1-0.5 mm, 0.5-0.25 mm and < 0.25 mm sizes, but fertilization had no significant effect on the contents of water-stable aggregates. Long-term fertilization significantly increased the total organic carbon contents in different soil layers, and the application of organic fertilizer was higher than that of single chemical fertilizer. Long-term fertilization significantly increased the organic carbon contents of aggregate in 1-0.5 mm and 0.5-0.25 mm dry sieves of surface soil, and the increase of HMNPK treatment was the highest. The application of organic fertilizer had a positive effect on increasing the content of organic carbon in soil water stable aggregates, especially on the increase of organic carbon contents of 1-0.5 mm, 0.5-0.25 mm and < 0.25 mm diameter water stable aggregates, both of which were the largest in M treatment. Under the condition of rotation of wheat-maize in lime concretion black soil area, long-term organic fertilizer application could increase the content of total organic carbon, middle aggregates amounts and its organic carbon contents, which was beneficial to improve soil physical properties and soil fertility.