title: Nutrients, heavy metals and phthalate acid esters in solar greenhouse soils in Round-Bohai Bay-Region, China: impacts of cultivation year and biogeography.
abstract: Solar greenhouse is a common facility type used for horticultural crop production in China. However, most solar greenhouse fields have been degraded due to continuous cropping and excessive fertilizer use. Therefore, we investigated solar greenhouse soils covering a wide range of cultivation years and environmental conditions in Round-Bohai Bay-Region to test the effects of cultivation year and biogeography on nutrients, heavy metals, and phthalate acid esters (PAEs). In general, soil pH decreased while soil electrical conductivity (EC), organic matter (OM), total nitrogen (TN), NO3 (-)-N, NH4 (+)-N, mineral nitrogen (MN), Olsen-P, and NH4OAc-K contents increased as time of cultivation increased. However, this trend was influenced by sampling sites. Among sampling sites, Jiangsu showed a relatively low soil pH and high Olsen-P content, while Hebei showed a relatively high soil EC value, NO3 (-)-N, NH4 (+)-N, MN, and NH4OAc-K contents. Liaoning was characterized by relatively high soil OM and TN contents. The nutrient level indexes in evaluation of soil quality on Olsen-P and NH4OAc-K exceeded the standard seriously. The maximum values of the heavy metals Cd, Cu, and Zn were 4.87, 2.78, and 1.15 times higher than the threshold values, respectively. There was a rising trend on the heavy metal contents with the increasing cultivation years, and this trend was significantly influenced by sampling sites. Both Cu and Zn had relative high heavy metal indexes in evaluation of soil pollution. The PAEs were not detected in almost all sampling soils. Overall, the excessive fertilizer application was an important cause of nutrient accumulation and heavy metal pollution, resulting in soil degradation in solar greenhouses.
authors.affiliation: Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Yuanmingyuan West Road 2, Beijing, 100193, China.|College of Life Science, Linyi University, Shuangling Road, Linyi, 276005, China.
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Yuanmingyuan West Road 2, Beijing, 100193, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Tian
authors.affiliation: Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Yuanmingyuan West Road 2, Beijing, 100193, China. gaolh@cau.edu.cn.|Round-Bohai Bay-Region Collaborative Innovation Center for Protected Vegetables, Shenyang Agricultural University, Dongling Road 120, Liaoning, 110866, China. gaolh@cau.edu.cn.
authors.forename: Lihong
authors.identifier: http://orcid.org/0000-0002-4254-7042
authors.initials: L
authors.lastname: Gao
authors.affiliation: Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, Department of Vegetable Science, China Agricultural University, Yuanmingyuan West Road 2, Beijing, 100193, China. tianyq1984@cau.edu.cn.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Tian
mesh_terms: D000383:Agriculture; D061006:Bays; D002681:China; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis*; D010795:Phthalic Acids / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D010795:Phthalic Acids; D012987:Soil; D012989:Soil Pollutants; C032279:phthalic acid
keywords: Heavy metals; Phthalate acid esters; Round-Bohai Bay-Region; Soil nutrients; Solar greenhouse