Open Access

ARTICLE

Nitrogen and Phosphorus Pollutants Removal from Rice Field Drainage with Ecological Agriculture Ditch: A Field Case

by Lina Chen^1,2,3,4, Wenshuo Zhang¹, Junyi Tan^5,*, Xiaohou Shao¹, Yaliu Qiu⁷, Fangxiu Zhang^2,6, Xiang Zhang^2,6

1 College of Agricultural Engineering, Hohai University, Nanjing, 210098, China
2 Key Laboratory of Lower Yellow River Channel and Estuary Regulation, Ministry of Water Resources, Zhengzhou, 450003, China
3 Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China
4 College of Environment, Hohai University, Nanjing, 210098, China
5 Jiangsu Engineering Consulting Center, Nanjing, 210000, China
6 Yellow River Institute of Hydraulic Research, Zhengzhou, 450003, China
7Gaochun Water Resources Management Center, Nanjing, 211300, China

* Corresponding Author: Junyi Tan. Email:

Phyton-International Journal of Experimental Botany 2022, 91(12), 2827-2841. https://doi.org/10.32604/phyton.2022.024105

Received 24 May 2022; Accepted 10 August 2022; Issue published 29 August 2022

Abstract

Excessive nitrogen and phosphorus in agricultural drainage can cause a series of water environmental problems such as eutrophication of water bodies and non-point source pollution. By monitoring the water purification effect of a paddy ditch wetland in Gaochun, Nanjing, Jiangsu Province, we investigated the spatial and temporal distribution patterns of N and P pollutants in paddy drains during the whole reproductive period of rice. Then, the dynamic changes of nitrogen and phosphorus in time and space during the two processes of rainfall after basal fertilization and topdressing were analyzed after comparison. At last, the effect of the ditch wetland on nutrient purification and treatment mechanism, along with changing flow and concentration in paddy drains, was clarified. The results of this study showed that the concentrations of various nitrogen and phosphorus in the ditch basically reached the peak on the second and third days after the rainfall (5.98 mg/L for TN and 0.21 mg/L for TP), which provided a response time for effective control of nitrogen and phosphorus loss. The drainage can be purified by the ecological ditch, about 89.61%, 89.03%, 89.61%, 98.14%, and 79.05% of TN, NH₄⁺-N, NO₃⁻-N, NO₂⁻-N, and TP decline. It is more effective than natural ditches for water purification with 80.59%, 40%, 12.07%, 91.06% and 18.42% removal rates, respectively. The results of the study can provide a theoretical basis for controlling agricultural non-point source pollution and improving the water environment of rivers and lakes scientifically.

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Keywords

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