Effects of Drought Stress at Early Growth Stage on Response of Sugarcane to Different Nitrogen Application

The efficiency of nitrogen application may decline under the impact of drought stress at early growth stage. However, the information about the effects of nitrogen on sugarcane growth, yield and quality under such condition is still limited. In our study, the response of sugarcane to different nitrogen application levels under water stress condition was investigated. The experiment was conducted with four nitrogen application levels (0, 5.7, 11.4, 17.1 g pot−1) under two water regimes (well-watered at field capacity and drought stress at 1/3 available water). The result showed recovery of photosynthetic traits after re-watering from drought stress period at early growth stage. Drought stress significantly reduced the plant height, plant diameter, total leaves area, dry matter accumulation and sugar yield, but increased the concentration of Cl−, NH4 + and K+ in sugar juice. Applying nitrogen had positive effects on growth, agronomical and sugar parameters with lower juice ion concentrations. However, the efficiency of nitrogen fertilization was declined under drought stress condition.