Sustainability in Cereal Crop Production in Mediterranean Environments

The cContinuous increase of the world population (a growth of about one-third is expected by in 2050 will be about one-third more than today) joined together with the an even largermore marked increase in food demand (especially in emerging countries), will lead in the next thirty years to the necessity to produce 70% more food to keep pace with demand. To keep the pace mantain the pass with food demand, global cereal production would need to increase by 40 percent overall, or by some 900 million tons between the present and 2050. To sustain the increase in cereal production, Single countries can either increase production or increase net imports or a combination of both. The new challenge, therefore, to deal with tThis new global emergency, involvesing researchers, farmers, politicians, the agro-food industry and all steakholders the agro-food industry, and the new challenge can be summarized as follows: to produce more, but in a sustainable way. The goal of ''sustainable intensification" constitutes one of the priorities for the research in agriculture and one of the cornerstones of the new Common Agricultural Policy. In this context, all the techniques designed to maximize production through the more efficient use of resources, are in line with the objectives of “sustaining production able with minimal impact intensification”. In mediterranean environments, cereal crops are grown mainly in the semi-arid and sub-humid areas; Dry .In arid and semi-arid areas dry-land farming techniques isare of renewed interest in the view of sustainability, . Theyse techniques are to be applied in arid and semi-arid areas and are aimed to increase the water accumulation in the soil, reducetion of runoff and soil evaporation losses, the chooseice of species and varieties able to make better use of rainwater, rationalizeation of fertilization plans, sowing dates, weed and pest control. Fertilization plans should be based on well-defined principles of plant nutrition, soil chemistry and chemistry of the fertilizer elements. Starting from the calculation of nutrient crop uptake (based on the yield actually obtainable yield), dose calculation must be corrected by considering both the availability of the element in soil that interaction between fertilizer and the main physical and chemical parameters of the soil (pH , organic matter content, mineralization rate, C/N, ratio of solubilization of phosphorus, active lime content, presence of ions antagonist ions etc.). The choice of traditional, minimum andor no tillage is one of the most controversial aspects of agricultural research; Mmuch depends on soil texturetype (if sand or clay), crop type (depending mainly on the characteristics of the root), rainfall regime (mainly intensity) , long- period tillage plan, structural stability of the soil (in function of the organic matter content) and all other variables and their in the interaction between them. In any case, minimum and sod seeding are generally more economicless expensive and evidence points to a lower production of less CO2 producing respect to traditional tillage. Weed and pest control are also a critical point for the sustainability of cereal production: . The sustainabilityle weed and pest in control strategies involves should minimizinge the use of chemicals while safeguarding the yields. To this end, priority should be given to preventive and non- chemical agronomic measures, while and predict the chemical means should be used only when the level of weeds and pests exceeds the threshold of economic damage. Finally, precision farming technique is one of the most powerful toolsinstruments for the sustainability of cereal crop production. This technique helps the farmers in their decisions, taking into account the local variability of the physical, chemical and biological properties of the soil, as well as the timing of input application. With this management strategy, input of resources is balanced and optimized in order to increase the yields, and reduce interventions and costs; the environmental impact is significantly reduced, as well as it is reduced the amount of resources used for production.