This study evaluated the impacts of different irrigation-nitrogen (N) application strategies and N application rates on cotton growth and yield, agronomic N use efficiency (ANUE), and fertilizer-N fate in arid region. A split-plot design was employed to compare traditional irrigation and N application (TIN) with alternate partial root-zone irrigation combined with root-zone fertilization (ADI-RZF), under three N rates (0, 220, and 275 kg ha⁻¹). The results revealed that the seed cotton yield, harvest index (HI), ANUE, irrigation water productivity (WP I ) and fertilizer N recovery efficiency (FNRE) significantly increased under the ADI-RZF treatment relative to TIN. The expression of nitrate transporter genes ( GhNRT1.1 and GhNRT1.5 ) was upregulated by 2.3- and 2.7-fold in hydrated root zones under ADI-RZF, explaining the 34.7–52.9 % enhancement in FNRE. At N 220, the optimized ADI-RZF system achieved 95 % of the maximum yield potential (equivalent to the N 275 yield under ADI-RZF), while it reduced N input by 20 % and lowered the fertilizer N loss rate (FNLR) by 38.5–42.7 % compared to TIN at equivalent N rates. This reduction is attributed to the spatially targeted N placement in ADI-RZF, which minimized the soil residual N by 11.9–30.3 % through enhanced root foraging precision. In conclusion, ADI-RZF at the N 220 rate represents a sustainable strategy for cotton production in arid regions such as Xinjiang, China, effectively balancing high yield with a reduced environmental N footprint. • Cotton yield and photosynthetic rate were significantly enhanced via APRI combined with root-zone fertilization. • APRI with root-zone fertilization increased agronomic efficiency of N and irrigation water productivity. • The expression of GhPIP and GhNRT was up-regulated in the hydrated roots. • APRI with root-zone fertilization improved fertilizer N recovery efficiency while reducing fertilizer N loss rate.
Luo et al. (Wed,) studied this question.