9Ongoing climate change has been reported to have far-reaching impact on crop 10 development and yield in many regions of the globe including Europe. However, little is 11 known about the potential impact of climate change on specific stages of the crop cycle 12 including crop establishment, although it is a crucial stage of the annual crop cycles. For 13 the first time, we performed a simulation study to pinpoint how sugar beet sowing 14 conditions of the next eight decades will be altered under future climate change and if 15 these variations will affect sowing dates, germination and emergence as well as bolting 16 rates of this crop. We chose Northern France as an important study site, representative of 17 sugar beet growing basin in Northern Europe. Sugar beet emergence simulations were 18 performed for a period between 2020 and 2100, taking into account five sowing dates 19 (mid-February, 1 st March, mid-March, 1 st April and mid-April). Soil water contents and 20 temperatures in the 0-10 cm soil horizon were first simulated with the STICS soil-crop 21 model using the most pessimistic IPCC scenario (RCP 8.5) to feed the SIMPLE crop 22 emergence model. We also evaluated the probability of field access for the earlier sowings, 23 2 based on the amount of cumulated rainfall during February and March. When analyzed 24 by sowing date and for successive 20-year period from 2020 to 2100, there was a 25 significant increase in seedbed temperatures by 2°C after 2060 while no change in 26 cumulative rainfall was found before and after sowings, compared with the past.
27Emergence rate was generally higher for 2081-2100, while time to reach the maximum 28 emergence rate decreased by about one week, compared with other periods, due to higher 29 average seedbed temperatures. The rate of non-germinated seeds decreased, especially 30 for the earlier sowing dates, but the frequency of non-emergence due to water stress 31 increased after 2060 for all sowing dates, including the mid-February sowing. Bolting 32 remains a risk for sowings before mid-March although this risk will be markedly 33 decreased after 2060. The changes in seedbed conditions will be significant after 2060 in 34 terms of temperatures. However, the possibility of field access will be a main limiting 35 factor for earlier sowings, as no significant changes in cumulative rainfall, compared with 36 the past, will occur under future climate change. When field access is not a constraint, an 37 anticipation of the sowing date, compared to the currently practiced sowing (i.e. mid-
38March), will lead to decreased risks for the sugar beet crop establishment and bolting. The 39 use of future climate scenarios coupled with a crop model allows a precise insight into the 40 future sowing conditions, and provide helpful information to better project future farming 41 systems. 42 surface crust, temperature, water stress 44 phases of crop cycle are affected by several biotic and abiotic factors that may reduce seed 48 germination and seedling emergence rates (Lamich...