Effect of Growing Season Precipitation on Yield of Single Cropping Late Rice in Shanghai and Yield Estimation

In order to explore the effect of precipitation distribution on the yield of single cropping late rice in Shanghai, Precipitation Concentration Degree (PCD) and Precipitation Concentration Period (PCP) were used to study the nonuniform distribution characteristics of precipitation during the whole growth period of single cropping late rice from 1971 to 2015. The trend analysis method was used to study the precipitation distribution in the whole growth period of single cropping late rice and the relationship between the precipitation and yield in each growth period. Based on the CMIP5 Global Climate Model scenario’s precipitation forecast data, the precipitation on meteorological yield of single cropping late rice in Shanghai from 2020 to 2045 was estimated. The results showed that the changing trend of PCD in single cropping late rice-growing season was insignificant in the recent 45 years, and the distribution of precipitation was uneven. The PCP mainly concentrated from 27 July to 11 September, the booting and heading stages. The precipitation at tillering, booting, heading, and maturity stages were accounted for 29.9%, 26.2%, 7.1%, and 10.8% of the total growth period, and the precipitation at tillering and booting stages was accounted for more than half of the total growth period. There was a significant negative correlation between the precipitation at the booting stage and the meteorological yield of single-season late rice (p<0.05). In the next 30 years, the negative effect of precipitation on the meteorological yield of single cropping late rice will be slightly larger than the positive effect. That is to say, the effect of reducing production will be greater than that of increasing production. The precipitation variation during the single cropping late rice will impact the yield in the future climate change scenario, and the corresponding adaptive measures should be formulated.