| 摘要: |
| [目的]探讨NH4+-N回收率在不同因素下的变化规律.[方法]以黄土高原从北向南不同地区的典型土壤类型为对象,采用Bremner浸取法,研究了土壤类型、植被类型、施肥模式及添加有机物料对铵态氮回收率的影响.[结果]不同类型土壤及不同类型植被间NH4+-N回收率存在极显著差异(P<0.01).黄土正常新成土的NH4+-N回收率最高(88.8%),极显著大于其他土壤,土垫旱耕人为土的NH4+-N回收率最低(81.0%),简育干润均腐土和干润砂质新成土介于二者之间;不同类型植被间,林地土壤的NH4+-N回收率(91.0%)极显著高于其他类型植被土壤,其他类型植被土壤的NH4+-N回收率表现为农田(85.5%)>裸地(83.8%)>草地(83.6%),但三者之间差异不显著.添加有机物料后,土壤NH4+-N回收率极显著增加(P<0.01),不添加有机物料对照土壤的NH4+-N回收率为84.3%,添加长毛草和苜蓿后的NH4+-N回收率分别为86.6%和85.9%.长期施肥对土壤NH4+-N的回收率无显著影响(P=0.436 5>0.05).[结论]NH4+-N回收率与粘粒含量呈弱负相关,与有机质含量呈正相关,粘土矿物对NH4+-N的固定是土壤铵态氮回收率降低的主要原因. |
| 关键词: 黄土高原 NH4+-N回收率 土壤类型 有机物料 |
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| 基金项目:国家自然科学基金项目(90502006)；西北农林科技大学创新团队项目 |
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| Effect of soil type and organic material on NH4+-N recovery rate |
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| Abstract: |
| 【Objective】 The paper studied the change of NH4+-N recovery rate under different conditions,the effect of soil type,vegetation type,the model of fertilization and organic material on NH4+-N recovery rate.【Method】 In the experiment,the typical soils collected from north to south on loess plateau were chosen as the material,and the Bremner method was conducted.【Result】 The results showed that soil type, vegetation type,and organic material had remarkable influence on NH4+-N recovery rate (P<0.01).Averagely,the NH4+-N recovery rate of Los-Orthic Entisols was highest at 88.8%,Eum-Orthic Anthrosols was lowest at 81.0%.Hap-Ustic Isohumisols and Ust-Sandiic Entisols were in the middle.The NH4+-N recovery rate of forest soil,farmland soil,grassland soil,bare-land soil and grassland soil decreased accordingly at 91.0%,85.5%,83.8% and 83.6%,the lateral three ones were not significantly different,but they were remarkably lower than the forest soil.The NH4+-N recovery rate of reference (CK) soil without adding organic material was 84.3%,the NH4+-N recovery rate of soil with intaking Medicago sativa and Stipa bungeana were 86.6% ad 85.9% respectively,there was no significant difference between the two with organic matter, but they were significantly higher than reference soil.Long-term use of N and straw had no significant influence on NH4+-N recovery rate (P=0.436 5>0.05).【Conclusion】 Correlation Analysis indicated that NH4+-N recovery rate was negatively correlated with clay,but significantly positively correlated with organic mater,the sequestration of clay to NH4+-N was the main reason leading to the decreased NH4+-N recovery rate of NH4+-N. |
| Key words: loess plateau NH4+-N recovery rate soil type organic material |
