Quantitative information on the fate and efficiency of nitrogen (N) fertilizer applied to coarse textured calcareous soils in arid farming systems is scarce but, as systems intensify, is essential to support sustainable agronomic management decisions. A mesh house study was undertaken to trace the fate of N fertilizer applied to cotton (Gossypium hirsutum L. cv., Huiyuan701) growing on a reconstructed profile (0-100 cm) of a calcareous (>15% CaCO3) sandy loam soil. Two irrigation methods (drip irrigation, DI; and furrow irrigation, Fl) and four N application rates (0, 240, 360 and 480 kg/hm(2), abbreviated as N-0, N-240, N-360, and N-480, respectively) were applied. N-15-labelled urea fertilizer was applied in a split application. DI enhanced the biomass of whole plant and all parts of the plant, except for root; more fertilizer N was taken up and mostly stored in vegetative parts; N utilization efficiency (NUE) was significantly greater than in Fl. N utilization efficiency (NUE) decreased from 52.59% in N-240 to 36.44% in N-480. N residue in soil and plant N uptake increased with increased N dosage, but recovery rate decreased consistently both in DI and Fl. Plant N uptake and soil N residue were greater in DI than in FI. N residue mainly stayed within 0-40 cm depth in DI but within 40-80 cm depth in Fl. Fl showed 17.89% of N leached out, but no N leaching occurred in DI. N recovery rate in the soil-plant system was 75.82% in DI, which was markedly greater than the 55.97% in Fl. DI exhibited greater NUE, greater residual N in the soil profile and therefore greater N recovery rate than in Fl; also, N distribution in soil profile shallowed in DI, resulting in a reduced risk of N leaching compared to Fl; and enhanced shoot growth and reduced root growth in DI is beneficial for more economic yield formation. Compared to furrow irrigation, drip irrigation is an irrigation method where N movement favors the prevention of N from being lost in the plant-soil system and benefits a more efficient use of N.
