TY - EJOU AU - Cheng, Mingkun AU - Min, Ju AU - Zhang, Yanying AU - Wang, Yuhe AU - Wang, Xia AU - Shi, Weiming TI - Contributions of Volume and Concentration on Runoff Nitrogen Losses from Intensive Vegetable in China T2 - Phyton-International Journal of Experimental Botany PY - 2024 VL - 93 IS - 9 SN - 1851-5657 AB - Vegetable runoff nitrogen (N) loss is a serious environmental issue. However, whether the volume or N content of runoff determines the final N losses has not been clarified, which limited the optimal N managements in vegetable production. Here, we conducted a simulated rainfall experiment to study the runoff N loss flux pattern and the accumulation rate as well as the main influencing factors. The results showed that at 20 to 30 min, the volume of runoff water with a high N content reaches a critical inflection point of increase. Under 55 mm/h rainfall intensity, the N concentration decreased continuously. Under 75 mm/h, the soluble N concentration decreased during the first 25 min; thereafter, it stabilized. However, the total and particulate N decreased significantly after 30 min. Nitrogen losses via runoff from vegetable fields were from 18.5 to 26.0 kg/ha under two rainfall intensities. Runoff soluble N losses were mainly attributed to applied fertilizers (79.7%–95.5%), while particulate N losses were primarily originated from soil-retained N. Our data indicates that there was a significant difference in N losses pattern and influencing factors under varied fertilizer N inputs and rainfall intensities, which can help to optimize water and N fertilizer managements to mitigate non-point source N pollutants. In the future, long-term multi-site and -crop studies should be conducted to comprehensively clarify the N runoff losses in vegetable soils. KW - Non-point source pollution; N fertilizer; runoff rate; Raphanus sativus L DO - 10.32604/phyton.2024.054182