Optimizing water and nitrogen management to reduce basal nitrogen inputs, improve nitrogen uptake and utilization efficiencies, and achieve high yields and low soil nitrate residue in wheat production
Wen Li , Yuyan Fan , Qiu Yang , Wen Lin , Jianfu Xue , Yuechao Wang , Zhiqiang Gao
Crop and Environment ›› 2026, Vol. 5 ›› Issue (1) : 100113
Excessive basal nitrogen (N) inputs and improper water management limit both wheat yields and N use efficiency. Thus, a field experiment was conducted for two years to evaluate whether optimizing water and N management could reduce basal N inputs, improve N uptake and utilization efficiencies (NUpE and NUtE), and achieve high yields. A split-plot design was employed with water and N management as the main plots (conventional water and N management, CM; and drip fertigation, DF) and basal N rates as the sub-plots (150, 125, 100, 75, 50, 25, and 0 kg ha−1, designated as B150, B125, B100, B75, B50, B25, and B0, respectively), while maintaining a fixed topdressing N rate of 150 kg ha−1. The results showed that DF increased the average yield by 12.7-15.9% compared with CM due to improvements in N absorption, tillering ability, ear and grain numbers, leaf area index, and biomass production. More importantly, DF reduced the sensitivity of yield to the basal N rate. Halving the basal N rate from B150 to B75 reduced the yield by 4.1-4.3% under DF (P > 0.05), but the yield loss was 10.9-11.4% under CM (P < 0.05). Under DF, the increased grain weight compensated for the reduced grains m−2, but under CM, the 17.3-17.8% reduction in grains m−2 was not fully offset by the increase of 8.4-9.9% in the grain weight. In addition, the increased NUpE and NUtE also contributed to relatively high yield at B75 under DF. Furthermore, the NO3−-N residue under DF was 7.9-9.8% lower at B75 than at B150. In conclusion, DF combined with a reduced basal N rate is effective for increasing wheat production, while decreasing soil nitrate residual levels to mitigate environmental impacts.
Basal nitrogen rate / Drip fertigation / Nitrogen use efficiency / Soil nitrate / Wheat / Yield
| BN | basal nitrogen rate |
| CM | conventional water and nitrogen management |
| CV | coefficient of variation |
| DF | drip fertigation |
| LAI | leaf area index |
| N | nitrogen |
| NUpE | nitrogen uptake efficiency |
| NUtE | nitrogen utilization efficiency |
| SPAD | leaf relative chlorophyll content |
| WN | water and nitrogen management |
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