紫色土坡耕地硝态氮随壤中流迁移的时空分布模拟

龙天渝; 刘祥章; 刘佳

文章摘要

龙天渝,刘祥章,刘佳.紫色土坡耕地硝态氮随壤中流迁移的时空分布模拟[J].农业环境科学学报,2015,34(10):1973-1978.

紫色土坡耕地硝态氮随壤中流迁移的时空分布模拟

Modeling Spatial and Temporal Variation of Nitrate Loss via Interflow in a Sloping Field of Purple Soil

投稿时间：2015-04-23

DOI：10.11654/jaes.2015.10.019

中文关键词: 紫色土施肥方式硝态氮淋失数值模拟

英文关键词: purple soil fertilization method nitrate leaching numerical simulation

基金项目:"十二五"国家科技支撑计划重点项目(2011BAD31B03)

作者	单位
龙天渝	重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045 重庆大学低碳绿色建筑国际联合研究中心, 重庆 400045
刘祥章	重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045
刘佳	重庆大学三峡库区生态环境教育部重点实验室, 重庆 400045 重庆大学低碳绿色建筑国际联合研究中心, 重庆 400045

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中文摘要:

通过建立紫色土坡耕地耕作层和非耕作层土壤养分淋失的二维对流-弥散模型,针对全层施肥和基穴施肥两种方式,数值模拟坡耕地硝态氮淋失的时空分布.模拟结果表明:紫色土的壤中流发生在土壤饱和后的降雨中后期;硝态氮淋失在降雨初期全层施肥表现为垂直下渗,基穴施肥表现为由基穴向周围扩散,在降雨后期两者的养分淋失情况相似,壤中流成为硝态氮淋失的主要方式,并且二者耕作层硝态氮淋失速度均大于非耕作层;在相同施肥量(150 kg·hm^-2)条件下,降雨结束后,全层施肥耕作层土壤硝态氮浓度处于0.110~0.160 kg·m^-3,基穴施肥的硝态氮浓度处于0.040~0.120 kg·m^-3,因而基穴施肥的养分淋失多于全层施肥.

英文摘要:

A two-dimension convection-dispersion model was established to simulate the transport of nitrate in cultivated and non-cultivated layers in a sloping cropland of purple soil under broadcast incorporated and hole fertilization. Water transport in purple soil could be divided into saturation stage and interflow stage, and the interflow occurred during the middle and later period of rainfall when the soil was saturated. During the early period of rainfall, the loss of nitrate nitrogen was via downward infiltration under broadcast incorporated fertilization, while it was through diffusion from the holes under hole fertilization. During the later period of rainfall, however, losses of nitrate nitrogen were mainly via subsurface flow under both fertilization methods, with faster nitrate leaching in cultivated layer than in non-cultivated layer. At the same amount of fertilizer(150 kg·hm^-2), soil nitrate nitrogen concentrations were 0.110~0.160 kg·m^-3 under broadcast incorporated fertilization, but were 0.040~0.120 kg·m^-3 under hole fertilization, at the end of raining. The present results indicate that cumulative nitrate nitrogen losses are greater under hole fertilization than under broadcast incorporated fertilization.

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