Agricultural and Forest Meteorology 195–196 (2014) 1–11 Contents lists available at ScienceDirect Agricultural and Forest Meteorology j our na l ho me page: www.elsevier.com/locate/agrformet Climate change and its impact on agricultural potential in the central region of Argentina between 1941 and 2010 A.C. de la Casa ∗ , G.G. Ovando Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, Av. Valparaíso s/n (5000), Córdoba, Argentina a r t i c l e i n f o Article history: Received 3 December 2013 Received in revised form 20 March 2014 Accepted 15 April 2014 Available online 22 May 2014 Keywords: Climate change Water balance Agricultural suitability a b s t r a c t The productive characteristics and agricultural potential of a region are strongly related to its climate conditions, and these have changed in an unprecedented way worldwide in the last 70 years. While the warming since the late nineteenth century has been established as between 0.3 and 0.6 ◦ C, the varia- tion of other climatic elements such as precipitation, cloudiness and evaporation, has been much less explored. Climate change and variability in the central region of Argentina between 1941 and 2010 was studied, with special emphasis on water balance information, and the impact on agricultural suitability was assessed both temporally and spatially. Time series of 7 successive decades of climatic and agrocli- matic variables expressed spatially were used, with Sen’s nonparametric tests to assess the rate of change, and Mann–Kendall’s to establish the significance of the trend. While no major change was seen in the annual values of potential evapotranspiration (ETP), with significant rates that were positive in only 6% and negative in 2% of the territory, 57% of the territory presents an increasing total annual rainfall trend, which significantly reduced aridity. There is a general downward trend in water deficiency (Def), so that this indicator of aridity and productivity has negative rates over time (P < 0.10) in 25% of the territory, with a mean value of -33 mm decade -1 . The Moisture Index (IH) trend is positive in 99% and significantly positive in 42% of the region, marking wetter atmospheric conditions, especially up to the late twenti- eth century. Change in agricultural suitability was assessed by determining the variation of agroclimatic indicators of soybean crops at 4 sites in the production area. The results are spatially heterogeneous, with barely noticeable thermal and hydrological changes in Marcos Juárez, showing its more stable agrocli- matic aptitude, but more apparent changes in Ceres and Laboulaye. While water deficit explains the low agricultural aptitude until 1970, this deficit reduced between 1971 and 2000, increasing again in the last decade analyzed. The alternation that seems to be suggested, although not completely manifest yet, may be related to the oscillation of ocean indicators: the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO). Published by Elsevier B.V. 1. Introduction Atmospheric processes at different scales of time and space affect all activities of society, and civilization has evolved through different processes of adaptation to climate and environmental changes throughout history (Mannion, 1997). This interdepen- dence is particularly evident in agriculture, whose suitability and potential are subordinate to both the usual and the accidental atmospheric states that determine a region’s climate. Technolog- ical development seems to have given us the ability to directly or indirectly modify the state and condition of the atmosphere (Trenberth et al., 2007), producing a generalized state of concern ∗ Corresponding author. Tel.: +54 0351 4334103; fax: +54 351 4334114. E-mail address: delacasa@agro.unc.edu.ar (A.C. de la Casa). and alert which must be clarified in order to develop economically and environmentally sustainable farming. Agricultural activity in the central region of Argentina, and in Cordoba province in particular, has grown significantly in recent decades, reflected in a sustained increase in yields of major crops, as well as an increase in the farming area. This can be seen in Fig. 1, which shows the variation of the production, yield and planting area of major crops in Córdoba province. While much of the increase in corn and soybean production as from the 1970s can be explained by the steady increase in yields, the expansion in the area planted with these particular crops is also directly related to the increased production. The increase in corn and soybean area is necessarily linked to the advance of these crops into new territories. The simultaneously sustained increase of productivity and planting area can only be explained under climatic conditions that are better suited to the requirements of these crops. http://dx.doi.org/10.1016/j.agrformet.2014.04.005 0168-1923/Published by Elsevier B.V.