Simulation And Application Of DSSAT Model To Wheat Management Factors In The Chao Lake Basin

Chaohu Lake basin is the important Agriculture area in Anhui Provinceand Wheat growth occupies the main position in the structure of crop production. However, irrational fertilization, pest and disease impact, coupled with the changing natural climate phenomena, lead to low product quality and low yield. The environmental problems are a result of the slow process of traditional agriculture with slow socio-economic and sustainable development of Chaohu City.In recent years, information technology has progressively developed in agriculture,opening a new road for the traditional development of agricultural science and technology.. The crop model development and application provides a scientific and effective tool to promote the growth of the crop with a qualitative and quantitative analysis of growth transformation processes.It has systematic and universal mechanisms. Irrigation and fertilization are commonly available regulators to adjust the crop growth and predict crop yields under certain weather conditions.In this study, basing on the wheat experimental data from2007-2010in Zhonghan town. the seven genetic parameters for wheat was combinated with DSSAT4.0model to analyse sensitivity Model simulation were carried out for growth stages, leaf area index (LAI), yield, grain weight, above ground biomass, and straw quantity and compared with the experimental measured values. The calibrated wheat growth model of was used to simulate the growth and development for the conditions in2009-2010to simulate different sowing dates and planting densities. Different planting densities were simulated at different sowing dates. The optimum planting date and planting density was determined in2009-2010for the wheat yield and aboveground biomass production. The effect of the nitrogen fertilizer levels on the growth stage, yield, LAI and growth period of wheat was simulated.With the help of the above test, we can draw the following conclusions:1. Growth period: The simulation results for the three year (2007-2010) growth period are good most of the errors are within5%. For the three years the size of the simulation errors were1.71%,4.00%and8.05%. LAI: the simulated and observed LAI values for2007-2010are consistent for the three years for the four fertilizer treatments, i.e. the zero N, the conventional, the optimal, the N-30%treatment, simulated and observed in the wheat crop at tillering, jointing, booting, flowering, and maturity. From the point of view of N fertilization, the LAI can be rated in the order conventional> optimal fertilization> N-30%> zero N. Yield: the relative error between the simulated and measured yield values is relatively small for the three years2007-2010.2. Optimum density and sowing time were determined for2009-2010for conditions of Chaohu City. An optimum wheat seeding date is November7with a planting density of150plants/m~2, where under these conditions6,059kg/hm~2could be harvested. To get more total biomass harvest volume, the sowing date of November7with a plant density of150plants/m~2was determined. In that case, the aboveground biomass could reach14,332kg/hm~2.3. The2009-2010experiment showed that the wheat yield depends on N fertilizer, planting density and sowing date. The yield and LAI increased with the amount of applied N,Increasing range is degressive tendency. In different growth stages, the N content of different plant parts is different: at jointing: leaf N> stem N> root N> Grain N at flowering: leaf N> stem N> root N> Grain N at maturity: grain N> root N> stem N> leaf N at harvest: grain N> root N> stem N> leaf N.