title: Phosphorus saturation and mobilization in two typical Chinese greenhouse vegetable soils.
abstract: Chinese greenhouse vegetable production can cause eutrophication of fresh waters due to heavy use of fertilizers. To address this, phosphorus (P) leaching was compared between two major greenhouse vegetable soils from Jiangsu Province, Southeast China: clayey and acid-neutral Guli Orthic Anthrosols and sandy and alkaline Tongshan Ustic Cambosols. A total of 20 intact soil columns were collected based on differences in total P content varying between 1360 and 11,220 mg kg-1. Overall, six leaching experiments were carried out with collection of leachates over 24 h. Very high P concentrations, with a mean of 3.43 mg L-1, were found in the leachates from P rich Tongshan soils. In contrast, P leaching from fine-textured but less P rich Guli soils rarely exceeded the suggested environmental P threshold of 0.1 mg L-1. Strong linear correlations were found between different soil test P measures (STPs) or degree of P saturations (DPSs) and dissolved reactive P (DRP) for Tongshan soil columns. The correlations with Olsen P (r2= 0.91) and DPS based on MehlichIII extractable calcium (DPSM3-Ca) (r2= 0.87) were the most promising. An Olsen P value above 41 mg kg-1or a DPSM3-Caabove 3.44% led to DRP leaching exceeding 0.1 mg L-1. Accordingly, more than 80% of Tongshan soils resulted in DRP leaching exceeding the environmental P threshold. In conclusion P rich alkaline sandy soils used for greenhouse vegetable production are at high risk of P mobilization across China.
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark; Sino-Danish Center for Education and Research (SDC), China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. Electronic address: ykk@plen.ku.dk.
authors.forename: Yusef Kianpoor
authors.initials: YK
authors.lastname: Kalkhajeh
authors.affiliation: Sino-Danish Center for Education and Research (SDC), China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. Electronic address: bhuang@issas.ac.cn.
authors.forename: Biao
authors.initials: B
authors.lastname: Huang
authors.affiliation: Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China. Electronic address: wyhu@issas.ac.cn.
authors.forename: Wenyou
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark; Sino-Danish Center for Education and Research (SDC), China. Electronic address: peho@plen.ku.dk.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Holm
authors.affiliation: Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark; Sino-Danish Center for Education and Research (SDC), China. Electronic address: haha@plen.ku.dk.
authors.forename: Hans Christian
authors.initials: HC
authors.lastname: Bruun Hansen
mesh_terms: D002681:China; D004780:Environment, Controlled; D004784:Environmental Monitoring; D005068:Eutrophication; D005308:Fertilizers; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry*; D014675:Vegetables
chemical_list: D005308:Fertilizers; D012987:Soil; D012989:Soil Pollutants; D010758:Phosphorus
keywords: Degree of P saturation; Environmental P threshold; Eutrophication; Greenhouse vegetable production; Phosphorus leaching; Soil test P