The Availability and Accumulation of Heavy Metals in Greenhouse Soils Associated with Intensive Fertilizer Application.

Binggan Wei,Linsheng Yang,Zhiqiang Cao,Qing Chen,Min Meng,Jiangping Yu

doi:10.3390/ijerph17155359

Abstract

In China, greenhouse agriculture, which provides abundant vegetable products for human consumption, has been rapidly developed in recent decades. Heavy metal accumulation in greenhouse soil and products obtained have received increasing attention. Therefore, the availability and accumulation of cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) and their association with soil pH, soil organic matter (SOM), inorganic nitrogen (IN), total nitrogen (TN), available phosphorus (AP), and planting year (PY) in greenhouse soils were analyzed. The results showed that the mean concentrations of available Cd, Cu, Ni, Pb, and Zn were 17.25 μg/kg, 2.89, 0.18, 0.36, and 5.33 mg/kg, respectively, while their suggested levels in China are 0.6, 100, 100, 120, and 250 mg/kg. Cd, Cu, and Zn might be mainly originated from fertilizer application. A lower soil pH significantly increased the available Cu, Ni, and Zn concentrations and reduced Cd, Cu, Ni, and Zn accumulation. A higher AP significantly increased the proportions of available Cu, Ni, and Zn and elevated Cd, Cu, and Zn accumulation. There was a strong positive correlation between Cd, Pb, and Zn availability and TN, while IN was negatively related to the availability and accumulation of Cu and Zn. It was concluded that chemical fertilizer application increased the availability of Cu, Ni, Pb, and Zn and the accumulation of Cd, Cu, and Zn. Manure application clearly elevated the accumulation and availability of Cd and Zn in greenhouse soil.

Highlights

In China, agricultural soil has been extensively contaminated by heavy metals from anthropogenic activities, including fossil fuel combustion, mining, smelting, traffic, waste water irrigation, sewage sludge reuse, and fertilizer applications [1,2]
The results of this study showed that Cd, Cu, and Zn in greenhouse soils were mainly derived from fertilizer application
Soil pH clearly influenced Cd, Cu, Ni, and Zn availability and reduced the metal accumulation of the metals in greenhouse soils, while it was slightly correlated with the availability and accumulation of Pb

Summary

Introduction

In China, agricultural soil has been extensively contaminated by heavy metals from anthropogenic activities, including fossil fuel combustion, mining, smelting, traffic, waste water irrigation, sewage sludge reuse, and fertilizer applications [1,2]. The planting area of greenhouses was 2,082,880 ha in 2016 [3]. This provides an abundance of agricultural products, such as vegetables and fruits for human consumption. It has been reported that cadmium (Cd) contamination in greenhouse soil is more serious than that of the other metals. 41.5%, 54.5%, and 11.1% of soil samples from the respective southern, northern, and northwestern areas of China have higher Cd concentrations than the standard.

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