Search

Accurate crop development modelling is important in planning rational use of water resources and crop management, along with evaluating the effects of climate change on crop productivity and predicting yields. This study aims at modelling winter wheat productivity under different climatic scenarios and models, in a Moroccan rainfed agriculture site using the FAO AquaCrop model. The study site was a one-hectare experiment plot located in the Marchouch plateau in the North-western Morocco. The model was calibrated using field parameters of the crop growing cycle, the soil characteristics, the crop management and the observed yield for a period covering three cropping cycles (from 2014/2015 to 2016/2017) using daily rainfall and temperature data. The calibrated model was then used to simulate wheat productivity in the study site for short-term (2020-2030) and medium-term periods (2040-2050) compared to a reference (1985-2005). Two Representative Concentration Pathway scenarios (RCP 4.5 and RCP 8.5) were considered for three General circulation models (CNRM, EC-EARTH, and GFDL) to derive the average model outputs with focus on the crop yield, crop growing cycle and evapotranspiration. The results showed a good model calibration, with coefficient of determination R2 of 0.84, Nash-Sutcliffe indicator of 0.71 and Willmott index of 0.94. Simulations showed that under RCP 4.5 a short-term yield drop of 5.94%, a medium-term crop cycle decrease of 15 days and evapotranspiration reduction of 20mm. Meanwhile, the model predicted under RCP 8.5 a medium-term yield drop of 12.9%, a crop cycle decrease of 13 days and evapotranspiration reduction of 46mm. Overall, simulation results showed that AquaCrop model is suitable for simulating the effects of water and climatic stress on crop productivity in rainfed agricultural areas, which could help decision making in terms of water productivity and crop adaptation under future climate trends in the semiarid conditions., African and Mediterranean Agricultural Journal - Al Awamia, No 133 (2021)

This work deals with the digital soil mapping as a time and cost effective alternative for soil type characterization. The e-Soter (Soil and terrain) approach was used and validated for in the Khouribga-Kasbat Tadla semi-arid rainfed agricultural area of Central Morocco, covering 217.000 ha. The GIS processing included physiography and parent material as two soil genesis factors, added to field data from 90 soil profiles. A subset of the ASTER-GDEM 30m spatial resolution digital elevation model (DEM) was used to map three physiographic indicators that are slope gradient, relief index and potential drainage density. The parent material classification was derived from 1/100.000 geological map. The e-Soter hierarchical classification was then used to derive e-Soter homogenous units that were spatially joined to soil profile data in order to define the most representative soil type and delineate soil homogenous units at the 100.000 scale. The resulting soil map was validated in the field using a transect approach, with three transects in areas that were not included in the initial field data collection. Statistical significance for similarity between the map outputs and the field observations was confirmed using four statistical indices (Chi square, Cramér’s V, Fisher’s exact and Kappa reliability test), which confirms the validation of the e-Soter approach as a digital soil mapping tool in the study area., African and Mediterranean Agricultural Journal - Al Awamia, No 132 (2021): Agriculture Digitale - Spécial numéro