Sustainable management of a cropping system under salt stress conditions (Korba, Cap-Bon, Tunisia).

Korba is a coastal region and the main production area for strawberries, tomatoes, and peppers in Tunisia. Due to the use of saline groundwater in irrigation, soil salinization increases in the area. Farmers are therefore forced to reduce the salinity in the soil by adopting a suitable water management strategy "blended water," with the appropriate irrigation system "drip irrigation," and new farming techniques "crop combinations and crop rotations" to achieve sustainability. Based on the electrical conductivity (EC) of the groundwater (5.05 dS/m) and freshwater (1.7 dS/m), in our pilot plot, we determine that the blended water used in irrigation must contain 28.55% of groundwater with 71.45% freshwater to have a 50%strawberry yield potential because strawberry is the most salt-sensitive crop produced in the region. The strawberry-pepper's combination is a way to improve farmers' incomes with a 200% intensification rate, taking advantage of the rains and the availability of surface water during the wet season. However, the soil salinity used to increase under these crops from 1.28 dS/m in November 2018 to 3.04 dS/m of soil EC in September 2019. This is beyond the strawberry salt tolerance threshold (1 dS/m). Even after planting summer crops, tomatoes, and peppers, the rate of evolution of soil salinity exceeds 200% (~ 4.5 dS/m) and 122% (~ 3 dS/m), respectively. Therefore, the rotation becomes necessary to reduce the soil salinity and thus prepare the soil for the next planting of tomatoes, peppers, and strawberry-pepper's combination. The introduction of rainfed crops or fallow in the agricultural rotation system helped farmers to reduce soil salinity with about 56% and 67.2% for crop rotations including summer crops and the strawberry-pepper's combination, respectively, with a return period of 1 year.