果园土壤磷累积风险│SOIL TILL RES：长期过量施磷改变了酸性柚园土壤中的磷形态
编译：陈晓辉
原名：Long-term excessive phosphorus fertilization alters soil phosphorusfractions in the acidic soil of pomelo orchards
译名：长期过量施磷改变了酸性柚园土壤中的磷形态
期刊：Soil and Tillage Research
2020年影响因子：5.347
5年影响因子：6.368
在线发表时间：2021.10.05
第一作者：陈晓辉chenxiaohui0914@163.com
通讯作者：吴良泉liangquan01@163.com
第一单位：国际镁营养研究所/福建农林大学资源与环境学院
文章亮点
大量的磷累积在蜜柚园表层和亚表层土壤中
过量施用磷肥主要影响土壤中铁磷（Iron-bound P）和铝磷（Aluminum-bound P）的浓度
土壤中易溶态磷（SolutionP）和铝磷的浓度与土壤奥尔森磷（Olsen P）浓度高度相关
当蜜柚园土壤中的磷盈余达到4128kg P ha-1将会增加土壤磷流失的风险
高度集约化果园的土壤中累积磷的耗竭值得研究
文章正文
【研究背景】
长期过量施磷对果园土壤磷形态变化和磷流失风险的影响尚不清楚。
【研究方案】
研究人员于2018年调研并采集了位于福建省漳州市平和县不同施肥年限（原生林，小于10年，大于10年）的蜜柚园土壤，同时结合室内土壤培养试验，探究施肥年限（或土壤磷累积量）对土壤中的全磷、Olsen-P及不同磷组分的浓度变化及其之间的关系。
Fig. S1.Distribution of sampling points in the pomelo orchard (PO) and background wasteland (BG). Note: The soil from 5 sampling points in the same soil layer wascombined, and then, approximately 500 g of soil was collected as one soilsample by the quartering method. Three sampling points were randomly set ineach PO and BG.
Table S1.Annual fertilizer application in the surveyed pomelo orchards (PO, n = 10)
Table S2.Basic physical and chemical properties in the 0-20 cm soil horizon of thebackground (BG, n = 8), young pomelo orchard (YPO, n = 4) and old pomeloorchard (OPO, n = 6)
Fig. 1.Location of the study area (A), conventional fertilizer practices (B), andextensive fertilization methods (C) and landscape (D) of pomelo orchards (POs)in Pinghe County, Zhangzhou City, Fujian Province, China. Note: The circlednumbers from 1 to 6 in B refer to the general orchard management procedures oflocal pomelo farmers.
Fig. 2.Soil inorganic P (Pi) fraction sequential extraction method and soil organic P(Org-P) determination method.
【研究结果】
在我国典型的亚热带柚子种植区，磷肥施用量远远超过要求，这导致土壤磷大量积累。柚园土壤中的TP和Olsen-P浓度显著高于未耕地。
随着种植（施肥）年限的增加，土壤中的速效磷不断向土层深处移动，Al-P和Fe-P逐渐成为主要的磷库。与Olsen-P关系最密切的土壤磷组分为Al-P，其次为Sol-P、Fe-P、Ca-P、Org-P和Red-P。然而，只有Sol-P和Al-P对Olsen-P有重要的直接影响。当土壤磷剩余量超过4128 kg P ha-1时，即按照当地施肥习惯计算，大于12年的果园就会面临急剧增加的磷淋失风险。
Fig. 3. Annual balance and use efficiencyof phosphorus (PUE) nutrients (in P2O5) in the YPO and OPO based on farm surveydata. Note: The error bar indicates the standard errors.
Fig. 4. Changes in the soil TP and Olsen-Pcontents in surface (0–20 cm) and subsurface (20–40 cm) soils in the BG, YPOand OPO. Note: YPO refers to young PO fertilized for less than ten years (n =4), OPO refers to old PO fertilized for over ten years (n = 6), BG refers tothe background field without any crop cultivation and fertilizer applicationnext to the PO (n = 8), TP refers to total phosphorus, Olsen-P refers tophosphorus extracted by NaHCO3. The error bar indicates the standard errors,letters in different colors (yellow refers to 0–20 cm and green refers to 20–40cm) indicate significant differences among different soil groups in the samesoil horizon (LSD, p < 0.05), and * denotes a significant difference amongdifferent soil horizons in the same soil group with the same fertilizationyears (LSD, p < 0.05).
Fig. 5. Changes in the concentration of Pfractions in BG, YPO and OPO surface (0–20 cm) and subsurface (20–40 cm) soils.Note: YPO refers to young PO fertilized for less than ten years (n = 4), OPOrefers to old PO fertilized for over ten years (n = 6), and BG refers to thebackground field without any crop cultivation or fertilizer application next tothe PO (n = 8). Sol-P refers to easily soluble P, Al-P refers to aluminum boundP, Fe-P refers to iron bound P, Red-P refers to reduction P, Ca-P refers tocalcium P, and Org-P refers to Organic P. The number at the top of the box plotindicates the average value, letters in different colors (yellow refers to 0–20cm and green refers to 20–40 cm) indicate significant differences amongdifferent soil groups in the same soil horizon (LSD, p < 0.05), and *denotes significant differences among different soil horizons in the same soilgroups with the same fertilization years (LSD, p < 0.05).
Fig. 6. Changes in the proportion ofdifferent P fractions to TP in surface (0–20 cm) and subsurface (20–40 cm)soils of BG, YPO and OPO. Note: YPO refers to young PO fertilized for less thanten years (n = 4), OPO refers to old PO fertilized for over ten years (n = 6),BG refers to the background field without any crop cultivation or fertilizerapplication next to the PO (n = 8). Sol-P refers to easily soluble P, Al-Prefers to aluminum-bound P, Fe-P refers to iron-bound P, Red-P refers toreduction P, Ca-P refers to calcium P, and Org-P refers to organic P.
Fig. 7. Relationship between P surplus andP fractions. Note: Sol-P refers to easily soluble P, Al-P refers toaluminum-bound P, Fe-P refers to iron-bound P, Red-P refers to reduction P,Ca-P refers to calcium P, and Org-P refers to organic P. *** indicatessignificance at p < 0.001
Fig. S2. Changes in the proportion ofdifferent P fractions to TP in different P surpluses.
Fig. S3. Relationship between Olsen-P and Pfractions.
Fig. 8. Correlation coefficient (A),variable importance projection (B) and path coefficient (C) between Olsen-P andP fractions. Note: Sol-P refers to easily soluble P, Al-P refers to aluminumbound P, Fe-P refers to iron bound P, Red-P refers to reduction P, Ca-P refersto calcium P, and Org-P refers to Organic P. In A, the data of the color spotsindicate the 2-tailed Pearson correlation coefficient (R), ** indicatessignificance at p < 0.01. In B, the value of the bars indicates the VIPvalue. In C, a straight line indicates that there is a direct effect on eachother, and the line with an arrow indicates a one-way direct effect. The valueon the line indicates the standardized path coefficients. The thickness of theline is positively correlated with the value of the path coefficients.
【结论展望】
本研究以蜜柚园为案例，进一步强调了集约化果园缺乏合理的磷养分管理。如何优化磷肥投入，同时充分利用土壤中的残留磷，进而减少磷资源浪费和磷流失风险，值得深入研究。
原文链接：
https://www.sciencedirect.com/science/article/pii/S0167198721002877