Work

Optimizing water–nitrogen coupling for quinoa yield, quality, and resource use efficiency in arid regions

Year: 2025

Type: article

Abstract: Introduction To investigate the effects of water–nitrogen coupling under drip irrigation on quinoa yield, quality, and water–nitrogen use efficiency, a microplot experiment was conducted in Aksu Prefecture, Xinjiang. Methods The study employed a two-factor factorial design with three irrigation levels ( W 1: 2,100 m 3 /ha, W 2: 2,700 m 3 /ha, W 3: 3,300 m 3 /ha) and five nitrogen application rates ( N 0: 0 kg/ha, N 1: 100 kg/ha, N 2: 125 kg/ha, N 3: 150 kg/ha, N 4: 175 kg/ha), resulting in 15 treatment combinations. Results and discussion Results indicated that under the W 1 irrigation level, increasing nitrogen application enhanced dry matter accumulation. However, under W 2 and W 3 conditions, dry matter declined when nitrogen exceeded 150 kg/ha, indicating a significant nitrogen threshold effect. A yield response model ( R ² = 0.945) predicted a maximum theoretical yield of 4,363.91 kg/ha at an irrigation volume of 2,931.59 m 3 /ha and a nitrogen application rate of 149.24 kg/ha. Optimal grain quality—characterized by fat content of 51.47–55.90 g/kg, protein content of 189.68–199.05 g/kg, and starch content of 581.23–585.96 g/kg—was observed under W 2 and W 3 combined with N 2 and N 3 treatments. Regression analyses indicated peak values for water use efficiency (WUE), nitrogen agronomic efficiency (NAE), and nitrogen partial factor productivity (NPFP) at 1.64, 29.72, and 31.92 kg/kg, respectively. Based on these findings, a recommended water–nitrogen management strategy for quinoa production in southern Xinjiang is 2,700 m 3 /ha of drip irrigation water combined with 150 kg/ha of nitrogen fertilizer, achieving a balance among high yield, resource efficiency, and environmental sustainability.

Source: Frontiers in Plant Science

DOI: 10.3389/fpls.2025.1654704