The SALTMED model is one of the few available generic models that can be used to simulate crop growth with an integrated approach that accounts for water, crop, soil, and field management. It is a physically based model using the well-known water and solute transport, evapotranspiration, and water uptake equations. In this paper, the model simulated chickpea growth under different irrigation regimes and a Mediterranean climate. Five different chickpea varieties were studied under irrigation regimes ranging from rainfed to 100 % crop water requirements, in a dry and a wet year. The calibration of the model using one of the chickpea varieties was sufficient for simulating the other varieties, not requiring a specific calibration for each individual chickpea variety. The results of calibration and validation of the SALTMED model showed that the model can simulate very accurately soil moisture content, grain yield, and total dry biomass of different chickpea varieties, in both wet and dry years. This new version of the SALTMED model (v. 3.02.09) has more features and possibilities than the previous versions, providing academics and professionals with a very good tool to manage water, soil, and crops.

In the Mediterranean region, crop productivity and food security are closely linked to the adaptation of cropping systems to multiple abiotic stresses. Limited and unpredictable rainfall and low soil fertility have reduced agricultural productivity and environmental sustainability. For this reason, crop management technologies have been developed, with a special focus on the Mediterranean region, to enhance crop production by increasing land productivity and sustaining soil fertility under influence of climate changes and population increases. The main objective of this study was to analyse dryland Mediterranean cropping systems, and to discuss and recommend sustainable cropping technologies that could be used at the small-scale farm level. Four crop management practices were evaluated: crop rotations, reduced tillage, use of organic manure, and supplemental and deficit irrigation. Among the tested interventions, incorporation of crop residues coupled with supplementary irrigation showed a significantly positive effect on crop productivity, yield stability and environmental sustainability.

This paper gives a glance about the conservation agriculture concept and the worldwide increase in agricultural area where this technique has been adopted. The main constraints to agricultural production in the Mediterranean region are discussed, highlighting the importance of conservation agriculture to mitigate them. Results of long-term studies with this technique, in Portugal, showed an increase in organic matter, improvement of aggregates stability and continuity of biological porosity along the soil profile. These changes in soil properties are helping to overcome edaphic and climatic constrains under Mediterranean conditions. The saturated hydraulic conductivity is improved allowing a better drainage during wet winters, and together with higher soil cohesion, the transitability of the soil is enhanced, allowing a correct timing of field operations like nitrogen top dressing and herbicide application. Nitrogen-use efficiency is improved either by the timing of application and by the improvement of soil organic matter content. Soil productivity is also enhanced and the overall energy-use efficiency is double when soil organic matter content is raised from 1 to 2 % in the top 30 cm of the soil. Therefore, conservation agriculture is advantageous from the economic and environmental point of view contributing to the sustainability of rainfed agriculture.

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