坡耕地红壤剖面磷的储存容量及其流失风险研究  

The Phosphorus Storage Capacity and Phosphorus Loss Risk of Red Soil Profiles in Sloping Farmland

作　　者：李欢 樊慧琳 张佳敏 王艳玲[1] LI Huan;FAN Huiling;ZHANG Jiamin;WANG Yanling(School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学应用气象学院,南京210044

出　　处：《土壤学报》2024年第1期98-109,共12页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(42077087)资助。

摘　　要：基于土壤磷储存容量的变化差异,准确评估与判断坡耕旱地与稻田红壤磷的剖面流失风险。以江西鹰潭孙家典型红壤小流域内位于坡上(T)、坡中(M)及坡下(B)的花生旱地(PU)及稻田(PF)各发生层土壤为对象,分析了各发生层土壤全磷(TP)、有效磷(Olsen-P)、磷饱和率(PSR)、磷吸持指数(phosphorussorptionindex,PSI)及磷储存容量(Soil phosphorus storage capacity,SPSC)随剖面的变化特征及差异,估测了坡耕地红壤磷的剖面流失风险,探讨了土壤pH、Eh及容重(BD)等因子对坡耕地红壤发生层SPSC的影响差异。结果表明,不同坡位花生旱地与稻田红壤表层TP、Olsen-P含量均显著高于底层土壤,且稻田红壤TP与Olsen-P的剖面变异显著高于花生旱地剖面。与耕作层(Ap1)相比,花生旱地底层土壤PSI显著增加了33.1%~146%,且随剖面深度增加而缓慢降低;而稻田红壤PSI则随着剖面深度增加而增大。花生旱地与稻田红壤(PF-M除外)PSR均随着剖面深度的增加而逐渐降低,SPSC变化范围分别为–89.2~298.3 mg·kg^(-1)与^(-1)38.1~101.1mg·kg^(-1)。PU-T与PU-M剖面SPSC均为正值,且随剖面深度增加呈降低趋势;而PU-B(耕作亚层Ap2除外)剖面的SPSC均为负值。PF-T(氧化还原层Br2除外)、PF-M(Ap1除外)及PF-B剖面各发生层的SPSC均为负值,且随剖面深度增加变化显著。基于SPSC理论对坡耕红壤剖面土壤磷储量及其环境流失风险的评估,花生旱地土壤磷沿剖面及坡位的迁移与运移迹象明显,当土壤Olsen-P>27.6mg·kg^(-1)时,花生旱地剖面土壤磷的流失风险将急剧增加,应及时采取管控措施。稻田红壤剖面各发生层均存在不同程度的磷流失风险,需立即停止施磷并及时采取有效措施。【Objective】The study aimed to assess and determine the P loss risk in red soil profiles of sloping upland and paddy fields based on the variation of soil phosphorus storage capacity(SPSC).【Method】The soil samples were collected from different pedogenic horizons in peanut uplands and paddy fields which were located at the top,middle and bottom of the slope in Sunjia small watershed,Ying tan,Jiangxi province of China.The profile variation characteristics of total P(TP),soil available P(Olsen-P),P saturation rate(PSR),P sorption index(PSI)and SPSC of tested soils were analyzed.Also,the effects of soil total carbon,total nitrogen,iron-aluminum oxides,pH,Eh and bulk density(BD)on the P loss risk of red soil profiles at different slope positions were evaluated.【Results】Soil TP and Olsen-P of the surface layer in peanut uplands and red paddy fields were significantly higher than those in the bottom layers and the profile variations of TP and Olsen-P in paddy fields were significantly higher than those in peanut uplands.Compared with the Ap1 layer,the PSI of peanut upland in the subsurface soils increased significantly by 33.1%~146%,and the PSI decreased with the increase of profile depth,but the PSI of paddy fields increased significantly with the increase of profile depth.The soil PSR of peanut upland and paddy field(except PF-M)decreased gradually with the increase of profile depth,while the variation ranges of SPSC were–89.2~298.3 mg·kg^(-1) and -138.1~101.1 mg·kg^(-1),respectively.The SPSC values of PU-T and PU-M were all positive,and they decreased with the increase of profile depth.Also,the SPSC value of all pedogenic horizons in PU-B(except Ap2)were all negative.The SPSC values of pedogenic horizons in PF-T(except Brs),PF-M(except Ap1),and PF-B were negative,and they changed significantly with the increase of profile depth.【Conclusion】Based on the assessment of soil phosphorus storage and its environmental loss risk in sloping red soil profiles by SPSC theory,the migration and transport signs

关 键 词：坡耕地 红壤 土壤磷储存容量 发生层 花生旱地 稻田 

分 类 号：S158.5[农业科学—土壤学] X825[农业科学—农业基础科学]