System for Identification of Maize Ideotypes, optimal sowing dates and nitrogen fertilization under climate change - PREPCLIM

According to the IPCC reports climate change has begun to be evident and the prospects appear more worrying today than a few decades ago. Although progress is being made in studying the impacts of climate change on crops and agricultural production, these are rarely directly applicable to provide future-validated solutions due to the extremely high complexity of factors that intervene at the local scale of the crop through atmosphere/soil/process interaction phenological/ecosystems, etc.

Providing an agro-ideotype requires the use of coupled climate-phenological modelling, at very high resolutions, capable of representing the processes involved at a very fine scale and extensive sensitivity simulations, performed under various projected climatic conditions and for a large number of combinations of the key phenological parameters (e.g. fertilization, sowing date, cultivar-dependent coefficients).

We present the implementation and validation of a new integrated climate / phenology / decision support (CPD) modeling system (based on CORDEX models / DSSAT model), a TLR4 system, developed under the frame of PREPCLIM project, and the results of system simulations carried out to identify the ideotypes for miaze in the near future climate (2050) for SE Europe/ Romania. Ideotyping with CPD system was carried out for an ensemble of genotyping codes (a genotyping code involed ~ 2000 simulations), for each testing alternate 12 treatments (4 planting dates and 3 fertilisation levels). The criteria for selecting optimal genotypes was according to user requirements: maximum production, stable production, minimizing the amount of leached nitrogen below the maximum level of the root front (reducing the risk of water table pollution), etc. The CPD system was validated for the southern area of Romania (Călăraşi) for the actual climate conditions. Projected changes in ideotype were simulated for two scenarios: RCP45 and RCP85 against historical simulations using an ensemble of three CORDEX models. The results for this ensemble indicate, for the control genotype, a mean decrease in production in both scenarios for all sowing dates and fertilisation levels tested, changes that were analised în relation to several factors: - a decrease (and time-shift) in the accumulated rainfall in the growing period, - a systematic earlier  flowering date and date of reaching physiological maturity, the two leading a shortening of the crop season; - a decrease in fertilization efficiency mainly for later  sowing dates and especially in RCP8.5. 

An open-source, operațional, user-interactive interface for this Agro-Climatic Service, în the support of agro-adaptation to climate change is operative under EERIS platform (eerir.eu/index.php)