摘要
以亚热带典型红壤性水稻土为研究对象,利用干筛法研究长期单施化肥和化肥配施有机肥对耕作层和犁底层土壤团聚体组成及其全氮储量分布的影响。结果表明:】5 mm的块状结构是土壤团聚体的主要组分,其含量比例高达65.7%~83.4%;同时,该级团聚体中全氮储量占土壤总储量的比例亦高达63.1%~82.7%,是土壤全氮储量的主要载体。随土层加深,块状结构体比例增加,其他粒级团聚体含量降低。除【0.25 mm粒级外,团聚体中全氮含量随其粒径减小而增大,而全氮储量则呈降低趋势。施肥特别是化肥配施有机肥后同土层0.25~5 mm大团聚体含量显著增加。团聚体稳定性增强,2~5、0.5~2、0.25~0.5 mm团聚体及土壤中全氮含量和储量显著增加(P【0.05),新增氮储量主要向大团聚体,特别是2~5 mm团聚体中富集。施肥对团聚体组成及其全氮含量的影响随土层加深而减弱。与单施化肥相比较,化肥配施有机肥显著提升犁底层和全层土壤全氮储量(P【0.05),是更好的施肥模式,可在亚热带红壤性水稻土分布区推广应用。
Fertilization greatly influences soil structure and nutrients accumulation in soil aggregates. In this study, the effects of long-term fertilization on aggregates composition and total nitrogen stock in a reddish paddy soil in the subtropical area of China were investigated. The fertilization treatments included CK(without fertilization), NK(nitrogen and potassium fertilizer application), NPK(balanced application of nitrogen, phosphorous,and potassium fertilizers), LOM(combined application of NPK and 30% organic manure fertilizers) and HOM(combined application of NPK and 60% organic manure fertilizers). Undisturbed soil samples in two layers were collected and then separated into five aggregate-size classes(>5 mm, 2~5 mm, 0.5~2 mm, 0.25~0.5 mm, <0.25mm) by the dry sieving method. The amount and storage of nitrogen in each aggregate fraction were measured.The results indicate that the >5 mm blocky fraction was the dominant aggregates component, accounting for65.7%~83.4% of dry soil mass in the two layers. It sequestrated 63.1%~82.7% of the total nitrogen in the soils and is considered the major carrier of soil nitrogen. Deeper in the soil, the content of >5 mm blocky fraction increased, while the percentages of the other aggregate-size groups decreased. For each soil layer, the contents of soil total nitrogen in different sizes of soil aggregates were significantly different and increased in the order of >5mm, 2~5 mm, 0.5~2 mm, 0.25~0.5 mm, and decreased from 0.25~0.5 mm to <0.25 mm. However, the total nitrogen storage value first decreased and then increased and the minimum value occurred in the size group of 0.25~0.5 mm. Compared to the CK treatment, long-term fertilization was in favor of increasing the proportion of aggregates in the size group of 0.25~5 mm, while reducing the aggregate fractal dimensions. Moreover, the total soil nitrogen contents and storages in 0.25~5 mm aggregates and in the whole soils were increased significantly(P<0.05) after fertilizer application and the effects show an increasing seq
出处
《地理科学进展》
CSCD
北大核心
2014年第10期1424-1432,共9页
Progress in Geography
基金
国家自然科学基金项目(41201297
41471114)
土壤与农业可持续发展国家重点实验室开放基金项目(0812201239)
湖南省教育厅科研项目(12C0827)
湖南省科技厅计划项目(2011NK3047)
湖南省产业经济学
应用化学重点建设学科项目(020205
081704)
关键词
长期施肥
红壤性水稻土
团聚体
全氮储量
亚热带
long-term fertilization
reddish paddy soil
aggregates
total soil nitrogen storage
subtropics
