干旱地区农业研究2013，Vol.31Issue(3)：100-105,6.
不同栽培模式及施氮量对土壤团聚体的影响
Effects of different cultivating patterns and nitrogen fertilizer application on soil aggregates
摘要
Abstract
The composition,distribution and stability of aggregate,and its relationships with soil organic carbon,soil moisture and yield were studied in a long-term fixed-location experiment.Different cultivating patterns(F,CC,SC,RF + SC) and different nitrogen fertilizer amount(N0,N120,N240) were tested to investigate their effects on soil aggregates in dryland of northwest China.The results showed that:ridge furrow + straw mulching pattern (RF + SC) planting significantly reduced the 0.25 ～ 10 mm dry-sieving aggregate content while significantly increased aggregate that is bigger than 10 mm,in comparison with conventional and straw mulching (SC) patterns.RF + SC pattern planting also promoted formation of bigger size aggregate from 0.5 ～ 5 mm one.Content of 0.25 ～ 10 mm aggregate by dry-sieving method was significantly higher in N240 treatment than in N0 treatment.Compared to conventional pattern,straw mulching significantly increased content of water stable aggregate with diameters greater than 0.25 mm.There were no significant differences in water stable aggregate with diameters greater than 0.25 mm among the different nitrogen fertilization treatments.Mean weight diameter (MWD) and geometric mean diameter (GMD) of soil aggregate by dry-sieving method were significantly higher in RF + SC pattern than in SC and conventional patterns.MWD of water-stable aggregate in SC pattern was significantly greater than in conventional patterns,and its GMD was also significantly greater than in RF + SC pattern.N0 treatment significantly improved GMD of water stable aggregate than N120 and N240 treatment; however,there was no significant difference in MWD among the three different N fertilizer treatments.Straw mulching and RF + SC patterns improved soil aggregate stability.There was no significant difference in aggregate stability among different nitrogen treatments.A significant positive correlation was observed between the average of water storage in 2 m soil profile over the 7 years and GMD of water stable aggregate,indicating that different planting patterns affect soil aggregation through its influence on soil water and that soil water condition is the determent factor affected soil water stable aggregate in this region.The correlation between average yield and GMD of water stability aggregate was significantly negative,indicating that small aggregate is benefit for crop yield.关键词
栽培模式/施氮量/土壤团聚体组成/平均重量直径(MWD)/几何平均直径(GMD)Key words
cultivating patterns/ nitrogen fertilizer/ soil aggregate composition/ geometric mean diameter (GMD)/mean weight diameter (MWD)分类
农业科技引用本文复制引用
周从从,陈竹君,赵世翔,周建斌,张晓敏..不同栽培模式及施氮量对土壤团聚体的影响[J].干旱地区农业研究,2013,31(3):100-105,6.基金项目
国家自然科学基金重点项目(30230230) （30230230）
国家"十一五"科技支撑计划课题(2008BADA4B09) （2008BADA4B09）
西北农林科技大学拔尖人才支持计划(2006) （2006）
