Evaluating the STICS Soil-Crop Model on durum wheat-chickpea intercropping system under the semi-arid conditions of Southern Tunisia
¹Gabes University, Higher Institute of the Sciences and Techniques of Waters of Gabes, Zrig, 6072 Gabès, Tunisia
²Eco&Sols, Univ Montpellier, CIRAD, INRAE, Institut Agro, IRD, 2 place Pierre Viala, 34060 Montpellier, France
³Department of Environmental Management, Institute of Environmental Engineering, RUDN University, 6 Miklukho-Maklaya Str., RU117198 Moscow, Russia
⁴Department of agronomy and agrotechnologies, Ryazan State Agrotechnological University Named after P.A. Kostychev, 1, Kostychev Str., RU390044 Ryazan Russia
⁵Laboratory of Biotechnology & Sustainable Development of Natural Resources, Polydisciplinary Faculty of Beni-Mellal, Sultan Moulay Slimane University,
Beni-Mellal 23000, Morocco
⁶Biology Department, College of Science, King Khalid University, P.O. Box 960,
62223 Abha, Saudi Arabia
⁷Agassiz Research and Development Centre, Agriculture and Agri-Food Canada, Agassiz, BC V0M1A0, Canada
⁸Center for Environmental Studies and Research, Sultan Qaboos University,
Al-Khoud 123, Muscat, Oman
*Correspondence: wissemhemdi@yahoo.fr
Abstract:
Soil-crop models provide critical insights for designing and assessing innovative cropping systems, particularly for improving sustainability in water-limited regions. However, accurately modeling intercropping systems particularly those involving grains and legumes continues to pose a significant challenge in agricultural research. This study focuses on the initial calibration and evaluation of the STICS soil-crop model for a durum wheat-chickpea intercropping system in Mediterranean semi-arid conditions. Field experiments were conducted during 2020–2021 and 2021–2022 cropping seasons in the Medenine region, Tunisia, with comparison between the intercropping and monoculture systems. The Model performance was evaluated using Aboveground Plant Nitrogen (AGPN) as an indicator of nitrogen uptake. The STICS model demonstrated satisfactory predictive capacity across most simulations, with efficiency (EFF) values ranging from 0.56 to 0.80. Grain yield predictions were reasonably accurate, as indicated by a normalized root mean square error (NRMSE) of ≤ 37%, particularly for durum wheat (EFF ≥ 0.55). The model effectively simulated the soil water content, achieving an efficiency (EFF) of ≥ 0.51 and an NRMSE of ≤ 25%, especially in the chickpea plots. However, the predictions of the soil nitrogen stock were less accurate in the chickpea monocultures, with efficiency values ≤ 0.38 and NRMSE ≥ 44%. The intercropping simulations showed moderate accuracy, with efficiency values up to 0.41. These findings highlight the potential complementary interactions between durum wheat and chickpeas in using nitrogen and carbon resources. This study contributes to the development of sustainable agricultural practices tailored to Mediterranean climates, supporting climate adaptation and resource efficiency.
Key words:
carbon, crop modeling, grain yield, nitrogen, soil water content, sustainable agriculture