Agro-phenological observation and modeling of cereals in Padana Plain in the period 2003-2012

Agro-phenological observation is a fundamental activity to obtain a significant and useful description of the seasonal development of crops, which is driven by environmental variables, among which temperature plays a primary role. The aim of this paper is to study the relation between thermal resources and phenological development in the agrophenological station of Cadriano (Bologna) on winter wheat, barley, maize and sorghum. This was achieved a) analysing eleven years (2003-2012) of phenological observations, expressed using the BBCH scale, and b) developing a thermal model based on Normal Heat Hours for phenological development of the four crops in Cadriano. Once the thermal model was calibrated it was used to evaluate the variability of thermal resources on a long time series (1984- 2013) recorded in the same site. The statistical analysis on the observed phenological data shows high stability, apart from the first stages, until the tillering of the winter crops. The phenological model evidences a satisfactory performance, in particular for summer crops, and a good correlation between phenology and thermal resources accumulation. Finally, the long time series analysis evidences an increase in time of thermal resources availability.