Rice plants were subjected to nitrate application and water disruption-induced drought treatments in a screen-house using pot culture, the urea application and ood treatments were used as controls. Nitrate (Ca(NO 3 ) 2 ) application signi cantly increased the ratio of NO 3 − -N to NH 4 + -N in the soil under both drought and ood treatments. Compared with urea application under ood treatment, both nitrate application and drought treatments caused yield losses. Under drought treatment, the yield loss of rice plant for nitrate application was 28.4% lower than that for urea application. The aboveground plant was smaller and more compact under nitrate application. Although nitrate application did not increase water uptake rate and xylem sap rate of the rice plant, nitrate application signi cantly stimulated the root growth of rice plant compared with urea application, especially under drought treatment, as indicated by higher root cap ratio, root biomass, root volume, root length, and density of lateral roots. Finally, the soil water potential decreased slower for nitrate application compared with urea application under drought treatment. The leaf water potential was higher for nitrate application compared with urea application under drought treatment. Our results indicated that rice plant developed a series of phenotypic adaptations to nitrate application and progressive drought, such as smaller and more compact aboveground plant, a less active but larger root system. These phenotypic adaptations made rice plant suffer less from the progressive drought stress resulting in a lower yield loss.

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