摘要
土壤磷储量及空间分布特征直接影响磷素的农业利用效率与生态环境安全,明确不同坡位稻田磷在各发生层及大小粒级团聚体内的储存格局及流失潜能,可为稻田土壤磷高效利用与流失风险管控提供科学依据。以江西鹰潭孙家典型红壤小流域内不同坡位的稻田剖面土壤为研究对象,分析了不同发生层土壤全磷储量(CTPs)、速效磷储量(CBray-P)、磷储存容量储量(CSPSC)及团聚体全磷储量(CTPa)的变化差异,评估了不同坡位稻田剖面磷的流失风险及影响因素。结果表明:不同坡位稻田剖面CTPs、CBray-P及CTPa均随发生层深度的增加先降低后增加,坡下稻田剖面CTPs及CBray-P均显著高于坡上及坡中剖面。各剖面中2—0.25 mm水稳定性团聚体的CTP2‒0.25 mm及贡献率(RC)均显著高于其他粒级(22.8—1120.9 kg·hm^(−2),4.97%—67.8%)。不同坡位稻田水耕表层(Ap1)的CSPSC为−209.5—−650.9 kg·hm^(−2),均存在磷流失风险;且随发生层深度的加深逐渐增加至418.5—1001.0 kg·hm^(−2),不存在磷流失风险;坡上稻田各发生层CSPSC的均值为390.9 kg·hm^(−2),显著高于坡中(145.6 kg·hm^(−2))及坡下(192.6 kg·hm^(−2))稻田各发生层的均值。通径分析表明,土壤有机碳对坡耕地稻田各发生层CSPSC起最直接的负向作用(直接通径系数为−0.903),而土层厚度、pH、游离铁氧化物与非晶质铁氧化物则起显著且直接的正向作用。
The storage and spatial distribution characteristics of soil phosphorus directly affect the agricultural utilization efficiency and ecological environmental security of phosphorus.Clarifying the storage pattern and the potential of loss potential of phosphorus in various aggregates and pedogenic horizons of red soil paddy at different slope positions can provide scientific basis for the efficient utilization and the loss risk control of soil phosphorus in paddy fields.The soil profiles of paddy fields at different slope positions in the typical red soil watershed of Yingtan and Sunjia in Jiangxi Province were studied;the variation differences of total P(CTPs),rapidly available P(CBray-P),soil P storage capacity(CSPSC)and aggregate P(CTPa)storage in different pedogenic horizons were analyzed;the loss risk and influencing factors of phosphorus loss in red soil profiles of paddy fields with different slope positions were evaluated.The results showed that the CTPs,CBray-P and CTPa in red soil profiles of paddy fields at different slope positions all decreased first and then increased with the increase of the depth of the horizons.The CTPs and CBray-P of the bottom slope paddy field profile were significantly higher than those of the top and the middle slope.The CTP2‒0.25 mm and RC of the 2−0.25 mm water-stable aggregates were significantly higher than the other grains(22.8‒1120.9 kg·hm^(−2),4.97%‒67.8%).The CSPSC of surface horizon(Ap1)of paddy fields in different slope positions was−209.5‒−650.9 kg·hm^(−2),all of which possessed the risk of phosphorus loss,and increased to 418.5‒1001.0 kg·hm^(−2) with the increase of the depth of horizon without the risk of phosphorus loss.The average of CSPSC in the top slope paddy field was 390.9 kg·hm^(−2),which was significantly higher than that in the middle(145.6 kg·hm^(−2))and bottom slope paddy fields(192.6 kg·hm^(−2)).The path analysis showed that soil organic carbon had the most direct negative effect(direct path coefficient was−0.903)on the CSPSC in the paddy fields,while soil thickness,pH,free Fe oxide and amorphous Fe oxide had significant and direct positive effects.
作者
樊慧琳
张佳敏
李欢
王艳玲
FAN Huilin;ZHANG Jiamin;LI Huan;WANG Yanling(School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,P.R.China)
出处
《生态环境学报》
CSCD
北大核心
2023年第2期283-291,共9页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(42077087)。
关键词
坡耕地
水稳定性团聚体
土壤磷储存容量
流失风险
发生层
red soil sloping farmland
water stable aggregate
soil phosphorus storage capacity
loss risk
horizons
