Effects of soil water stress on morphological development and yield of maize
土壤水分胁迫对玉米形态发育及产量的影响

Aridification might be enhanced under climatic change in the future, and it might seriously affect maize, one of main food and the most important forage crop in China. Understanding the possible responses of maize to drought is very important for making scientific strategies in order to mitigate negative effects of climatic change. Thus, simulating experiment on the responses of maize (Zea mays) to different soil water stress levels was conducted by pond cultivation at neutral loam, meadow soil. The soil water levels were designed as three levels by relative water content (RWC): 75 %( control, full water supply or well-watered), 55 %( moderate water stress) and 35 %( severe water stress) from maize seedling to maturity by controlling irrigation and the mobile rain shelter. The morphological characteristics, growth, development and yield of maize under different soil water levels and different growth stages would be analyzed in this paper. The results indicated that the intensities of the drought stress effects on maize rely on its drought intensity, drought duration and growth stage. The longer and more severe the water stress is, the more serious the effects on crop are. Moderate water stress would not change significantly its plant height and biomass production before the big flare period of maize; however, it would seriously decrease its height and biomass from big flare to tasselling as well as filling periods. Severe water stress would seriously affect its height and biomass production from shooting to filling periods. It would deteriorate its ear characteristics, and decrease significantly ear kernel number and 100-kernel weight as well as economic yield of maize. It implied that limited controlling water (moderate water stress) is feasible before big flare period of maize. The results also showed that drought stress before big flare period of maize would postpone obviously growth process of maize. Especially, severe water stress would delay 4 days or so for tasselling and silking stage compared to that under control treatment, and resulted in the postponement of its maturation.