Nutrient loss by runoff from rice-wheat rotation during the wheat season is dictated by rainfall duration

Lei Yan; Lihong Xue; Evangelos Petropoulos; Cong Qian; Pengfu Hou; Defu Xu; Linzhang Yang

doi:10.1016/j.envpol.2021.117382

Nutrient loss by runoff from rice-wheat rotation during the wheat season is dictated by rainfall duration

Environ Pollut. 2021 Sep 15:285:117382. doi: 10.1016/j.envpol.2021.117382. Epub 2021 May 19.

Authors

Lei Yan¹, Lihong Xue², Evangelos Petropoulos³, Cong Qian⁴, Pengfu Hou⁵, Defu Xu⁶, Linzhang Yang⁴

Affiliations

¹ Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of China, Nanjing, 210014, China; School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
² Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of China, Nanjing, 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212001, China.
³ School of Engineering, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
⁴ Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of China, Nanjing, 210014, China.
⁵ Jiangsu Academy of Agricultural Sciences, Key Laboratory of Agro-Environment in Downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of China, Nanjing, 210014, China; School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, 212001, China. Electronic address: pengfuhou100smby@163.com.
⁶ School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China.

PMID: 34049130
DOI: 10.1016/j.envpol.2021.117382

Abstract

Clarifying the properties/features of nutrient loss from farmland surface runoff is essential for the mitigation of nutrient losses. Plough pan formation underneath topsoil is a common feature of long-term paddy soils that significantly affects water movement and nutrient runoff loss, especially during the upland season of paddy-upland rotation. To characterize the nutrients that are lost from wheat fields of paddy-wheat rotation with runoff, a field experiment was conducted in a wheat field using a simulated rainfall system from November 2019 to May 2020 in Nanjing, China. The aim of this study was to investigate the temporal characteristics of nitrogen (N) and phosphorus (P) loss under different rainfall intensities (low, 30 mm h^-1; middle, 60 mm h^-1; high, 90 mm h^-1). The results showed that the time interval from the beginning of rain to the occurrence of runoff (time to runoff, Tr) was negatively correlated with "rainfall intensity" (Ri) (P＜0.01) but unaffected by soil moisture. Different rainfall intensities had no effect on the runoff coefficient (the ratio of the runoff volume over the precipitation, 0.14-0.17). The N and P loss concentrations in the nutrient discharge followed a power-function relationship that decreased over time (P＜0.01), and the peak nutrient concentration appeared during the initial runoff period (0-5 min). The N and P loss rates were the highest during the middle-to-late discharge period (15-30 min) for all intensities. In terms of cumulative nutrient losses, the amounts of TN lost were similar for all rainfall intensities, while TP significantly increased with intensity. The results revealed that nitrate-nitrogen (NO_X^--N) and particulate phosphorus (PP) were the predominant forms of N and P losses. Overall, during the initial runoff period, nutrient concentration peaks, whereas the nutrient loss rate is the highest during the middle-late phase of the phenomenon.

Keywords: Nutrient loss; Paddy-upland rotation; Plough pan; Simulated rainfall; Temporal characteristics.

MeSH terms

China
Nitrogen / analysis
Nutrients
Oryza*
Phosphorus / analysis
Rain
Rotation
Seasons
Soil
Triticum*
Water Movements

Substances

Soil
Phosphorus
Nitrogen