| There will be more areas prone to drought with climate change, which could lead to the chance of instability of grain production, even endangers regional and global grain security. Nowadays drought of maize has drawn public attention with the expansion of maize planting area. Maize is very sensitive to the water conditions in the whole growth period. Water deficiency would affect plant growth, which could lead to a decline in economic yield and biomass. WOFOST model, widely used in agricultural meteorological study with its strong machine rational, is an effective technology to the research on maize drought, with its application to overcome difficult to accurately control the moisture field moisture control experiment in water simulation studies.This study used Jilin province as the study area, analyzing the influence to Jilin spring maize growth in different moisture conditions, using crop model to simulate plant development under different growth period and moisture conditions based on actual conditions, is to explore the plant development and production response in different degree of water shortage and re-watering conditions. The main outcomes in this study are as follows:(1) The results indicated that the drought frequency of Sowing-seedling was highest in the Midwest of Jilin province. Drought occurred in highest frequency at the stage of Jointing-tasseling in east area. In the view of spatial scale, the drought classes of spring maize crop reduced gradually from west to east. In the view of time,the drought class at the stage of Sowing-seedling was highest than another stages.Special drought occurred in west areas in 1975 and 2004, in middle area in 2001, in sowing-seedling stage. In Seedling-jointing and Jointing-tasseling stage, a high level drought class occurred in west and middle areas from 2001 to 2004. In Tasseling-milky maturity stage, special drought occurred in west area in 2004. In Milky maturity-full maturity stage,heavy drought occurred in west area in 2007.(2) Based on the field experiment data of spring maize in Jilin representative site, the computer simulation and other methods were used to calibrate parameters of WOFOST model and compared with crop model. Results show the model calibrated can effectively simulate the spring maize growth in a normal year; data in typical years was selected to verify the model in limited soil moisture condition. The results show the WOFOST model with adjustable parameter can well simulate growth and yield of spring maize in drought year.(3) Based on the adjusted model,drought effect to spring maize was studied.The results show in Jointing-tasseling and Tasseling-milky stage, the loss of spring maize aboveground dry biomass and the production gradually increasing with the increase of drought degree and the delay of re-watering time. The loss of aboveground dry biomass in Jointing-tasseling stage is severer than in Tasseling-milky maturity stage under similar drought and re-watering time condition.In same drought condition, the yield loss in Tasseling-milky maturity stage is more serious than in Jointing-tasseling stage. From the view of yield reduction rate, the drought occurred in Tasseling-milky maturity stage has more serious effects on plant.This study discusses the impact to maize growth by moisture. Results can provide positive data assistance with protecting spring maize crop in Jilin province from drought in different growth stages, and it is greatly significant for production of maize in the use of water. And provide the basis for supplementary irrigation and farmland water management in the actual production. |
PDF Full Text Request