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| Risk assessment of heavy metals accumulation in soils under long-term greenhouse vegetable cultivation conditions |
| Received:January 29, 2018 |
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| KeyWord:soil heavy metals;cumulative risk;pollution evaluation;organic planting;long-term location experiment |
| Author Name | Affiliation | E-mail | | LI Jie | College of Resources and Environment, China Agricultural University, Beijing 100193, China | | | ZHU Ling | College of Resources and Environment, China Agricultural University, Beijing 100193, China | | | TONG Li-hong | College of Resources and Environment, China Agricultural University, Beijing 100193, China | | | LÜ Yi-zhong | College of Resources and Environment, China Agricultural University, Beijing 100193, China | lyz@cau.edu.cn | | LI Ji | College of Resources and Environment, China Agricultural University, Beijing 100193, China | |
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| Abstract: |
| The effect of different planting modes on soil heavy metals contents was investigated in this study. The differences in the contents of Cu, Zn, Pb, Cd, Cr, As and Ni in soil under long-term greenhouse organic planting (ORG), low-input planting (LOW) and conventional planting (CON) conditions were compared. The accumulation and ecological risks of heavy metals in soil were evaluated using the single factor index method, Nemero comprehensive accumulation index method and potential ecological risk index method. The results showed that the heavy metals accumulation in the soil was significant after 15 years of the planting exercise utilizing the three planting modes. The accumulation of Cd in soil was the most significant among the investigated heavy metals, increasing by 312.50%, 175.00% and 100.00% for ORG, LOW and CON, respectively. Only the Cd content under ORG and LOW was found to exceed the environmental quality assessment standard of greenhouse vegetable production, whereas none of the other heavy metals exceeded their standards, albeit with accumulation of each to some extent. Taking into account the initial value as reference, the evaluation results showed that there was a high risk of heavy metal accumulation in soil under ORG, and the accumulation index of heavy metals was ordered as ORG > LOW > CON. Considering the standard values for greenhouse vegetables, the heavy metal contents in soil did not cause any ecosystem risks after 15 years of long-term planting. In addition, the comprehensive ecological risks of the three planting modes were generally minor, with the ecological risk index ordered as ORG > LOW > CON. Therefore, quality control of organic fertilizer should be strengthened to ensure the healthy development of organic agriculture. |
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