摘要
横坡垄作是坡耕地广泛采用的水土保持措施,垄沟内雨水的汇聚和泥沙沉积,使得土壤氮的空间分布特征明显有别于传统耕作坡面。以北方土石山区横坡垄作坡面为研究对象,样带法采集土壤样品,基于经典统计、地统计学、Kriging插值等方法,分析垄面、垄沟等特征点位全氮(TN)、硝态氮(NO_(3)^(-)-N)、铵态氮(NH_(4)^(+)-N)含量沿坡位变化及其剖面分布,明晰横坡垄作坡面土壤氮的空间分布特征。结果表明:北方土石山区土壤氮含量属于中低水平,变异系数介于17.64%~33.60%,但垄面土壤氮的变异水平高于垄沟。TN含量沿坡位的变异最为显著,表现为坡下>坡脚>坡中>坡上;仅垄沟NO_(3)^(-)-N、NH_(4)^(+)-N含量沿坡位存在显著变化,坡脚NO_(3)^(-)-N、NH_(4)^(+)-N含量较其他坡位显著增加66.30%~83.85%。垄面与垄沟间氮含量的差异在坡上、坡下和坡脚体现的较为明显;与垄沟相比,垄面坡上TN含量减少21.34%,坡脚NO_(3)^(-)-N和NH_(4)^(+)-N含量减少17.42%~37.47%,坡下土壤氮含量增加21.56%~38.16%。TN剖面分布与坡位和特征点位有关,NO_(3)^(-)-N、NH_(4)^(+)-N的剖面分布主要受控于特征点位,但氮含量剖面分布符合指数函数关系。综上,横坡垄作坡面土壤氮空间异质性明显,且主要受控于特征点位和坡位。研究结果可为提高横坡垄作措施下氮肥利用效率、精准农业的顺利推广提供技术支撑。
Contour ridging is a widely used soil conservation practice for slope farmland.Rainwater from side slopes ponding and deposition sediment in the furrow areas could induce the spatial distribution of soil nitrogen on slope within contour ridge system differ from that on traditional slope.Based on line sampling method,this study analyzed the contents of total nitrogen(TN),NO_(3)^(-)-N and NH_(4)^(+)-N and their profiles distribution in ridges and furrows along with slope positions in order to determine the spatial distribution of soil nitrogen within contour ridge system in rocky mountainous areas of Northern China by the classical statistical and geostatistical methods.Results showed that soil nitrogen content in topsoil of rocky mountainous areas of Northern China was at the middle level.The variation coefficients of soil nitrogen ranged from 17.64%to 33.60%,and the variation in ridges was greater than that in furrows.The variation of TN content was the most significant with the change of slope positons,and was in order of downslope>toe slope>middle slope>upslope.However,the content of NO_(3)^(-)-N and NH_(4)^(+)-N in furrows at toe slope statistically increased by 66.30%~83.85%relative to other three slope positions,and no significant difference in ridges was observed among slope positions.In addition,the difference in soil nitrogen contents between ridges and furrows mainly reflected at upslope,down slope,and toe slope.Compared to furrows,TN content in ridges at upslope decreased by 21.34%,and NO_(3)^(-)-N and NH_(4)^(+)-N in ridges at toe slope decreased by 17.42%~37.47%,but soil nitrogen content in ridges at down slope increased by 21.56%~38.16%.Furthermore,the profile distribution of TN was related to slope position and feature point,but NO_(3)^(-)-N and NH_(4)^(+)-N profiles distribution were mainly controlled by feature points.Meanwhile,exponent function fitted the relationship between soil nitrogen content and soil depth.Thus,the pronounced heterogeneity existed for the spatial distribution of soil nitrogen within contour ridge system,which was determined by feature points and slope positions.These findings supply technological guidance for the improvement of nitrogen use efficiency within contour ridge system and the smooth promotion of precision agriculture.
作者
安娟
宋红丽
类宏程
窦永辉
周旭
AN Juan;SONG Hong-li;LEI Hong-cheng;DOU Yong-hui;ZHOU Xu(Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection,College of Resources and Environment,Linyi University,Linyi Shandong 276005;Yunmeng Lake Ecological Region Management Committee,Linyi Shandong 276005)
出处
《中国土壤与肥料》
CAS
CSCD
北大核心
2023年第7期69-77,共9页
Soil and Fertilizer Sciences in China
基金
水利部黄土高原水土保持重点实验室开放课题(WSCLP202103)
国家自然科学基金面上项目(41977067)。
关键词
土壤氮
垄面与垄沟
坡位
空间分布
横坡垄作
soil nitrogen
ridge and furrow
slope position
spatial distribution
contour ridge system
作者简介
通讯作者:安娟(1982-),教授,博士,主要从事土壤侵蚀机理研究。E-mail:anjuan0715@126.com。
