Abstract: In order to obtain the composite meteorological index of rice suitable nursery and transplanting date in Hetao irrigation area, the genetic parameters of Ningjing 16 were debugged by CERES-Rice model using the agrometeorological data observed from 1996 to 2003 in Zhongwei. The rice yield, the number of grains per m2, the period from sowing to flowering, and the whole growth period were simulated, and the model regional simulation ability was verified by the data of 10 counties and cities in irrigation areas of Ningxia. Setting different nursery days and shed temperature, the separate and comprehensive effects of the two factors on the yield, grain number per square meter and the growth process were simulated to determine the comprehensive meteorological indexes suitable for transplanting date. The results showed that the model had a good simulation ability for rice yield, grain number, sowing to flowering days and whole growth period. The maximum errors of yield and grain number were 2.93% and 3.47%, and the consistency index was up to 0.98 and 0.92, respectively. The simulation error of sowing to flowering period was mostly within 3 days, and the consistency D index was 0.77. Assume that the meteorological conditions, fertilization, irrigation and other measures were unchanged after transplanting, set different nursery period and shed temperature, simulation results showed that the yield and grain number in 26-30d nursery was higher than that in 18-24d. Under the condition of 32℃, the yield and the number of grains were the highest, and the number of days from sowing to flowering and the whole growth period was relative short. At the same time to change the nursery period and the shed temperature, under the short seedling period condition, raising the shed temperature increased the yield and the grain population. While the long seedling period condition, raising the shed temperature caused the decline in production and grain number. Under the condition of 32℃ and 20d, the yield was the highest, the grain population was the most, the period from seeding to flowing and the whole growth were relatively short. The days from sowing to flowing and the whole growth period under the same nursery period were shortened with the increase of shed temperature, but shortened with the extend of nursery period under the same shed temperature. The optimum nursery period was obtained at different shed temperatures, which could be used as a comprehensive agrometeorological indicators to predict the suitable transplanting date at different county in Hetao irrigation area. The results provide a new way to refine the comprehensive agricultural meteorological index of suitable transplanting period.

Key words: CERES-Rice model, Nursery period, Shed temperature, Growth period, Yield