| This article has been：Browse 206Times Download 33Times |
scan it! |
|
|
| DOI：10.13522/j.cnki.ggps.2026068 |
|
| Effects of fertilization rate on soil nitrogen dynamics and rice yield under shallow-wetting-drying irrigation |
|
Qiu Yuqing, Tong Juxiu, Wang Mingkuan, Wu Jingwei
|
|
1. MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing),
Beijing 100083, China; 2. School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China;
3. State Key Laboratory of Water Resources Engineering and Management, Wuhan University, Wuhan 430072, China
|
| Abstract: |
| 【Objective】Optimizing fertilization under water-saving irrigation can improve rice yield and nitrogen- use efficiency while reducing nitrogen losses. This study investigated the effects of fertilizer application rate on soil nitrogen dynamics and rice yield under shallow-wetting-drying irrigation to find an optimal irrigation–fertilization strategy for simultaneously improving rice yield and nitrogen-use efficiency.【Method】The experiment was conducted in five paddy fields under shallow-wetting-drying irrigation. Fertilization treatments were as follows: slow-release fertilizer (N∶P∶K= 24∶8∶10), urea (N＞46%), and compound fertilizer (N∶P∶K = 26∶10∶15) were applied as basal fertilizer and topdressings at the jointing and booting stages, respectively. Fertilizer application rate in four fields was set at 100%, 90%, 85%, and 80% of the conventional fertilization rate, and one unfertilized field served as the control. The spatiotemporal distributions of NH4?-N and NO3--N in the 0-30 cm soil layer, as well as rice yield and nitrogen-use efficiency, were measured for each treatment.【Result】NH4?-N and NO3--N concentrations peaked following each fertilizer application. NO3--N concentrations were significantly lower than NH4?-N concentrations, and the peak in NO3--N concentration generally lagged behind that of NH4?-N, except under the conventional fertilization rate. Overall, reducing fertilization rate by 10% relative to the conventional fertilization rate resulted in the most stable spatiotemporal distributions of NH4?-N and NO3--N, and achieved the highest rice yield and nitrogen-use efficiency.【Conclusion】Under shallow-wetting-drying irrigation, reducing fertilizer application by 10% relative to the conventional fertilization rate was most effective, increasing both rice yield and nitrogen-use efficiency. This irrigation-fertilization strategy reduced nitrogen losses through gaseous emissions and leaching by regulating the spatiotemporal dynamics of soil nitrogen. |
| Key words: shallow-wetting-drying irrigation fertilizer application levels nitrogen transport rice yield paddy field |
|
|
