Abstract
The present rates of yield growth and overall production are not sufficient to satisfy the food demand of growing population as more than 820 million people in the world are still hungry today and about 2 billion people in the world experience moderate or severe food insecurity, thus making in challenging of achieving the Zero Hunger target by 2030..Further the climate change has added to the enormity of India's food security challenges by affecting food production by water scarcity or thermal stress. Thus under the present scenario of limited resources, challenges of climate change, exploding population, food insecurity the multiple approaches must be employed to meet the demand of the growing population under climate change scenario. One such approach is to use crop simulation models. A Crop Simulation Model (CSM) is a simulation model that describes processes of crop growth and development as a function of weather conditions, soil conditions, and crop management. Typically, such models estimate times that specific growth stages are attained, biomass of crop components (e.g., leaves, stems, roots and harvestable products) as they change over time, and similarly, changes in soil moisture and nutrient status. They are dynamic models that attempt to use fundamental mechanisms of plant and soil processes to simulate crop growth and development. The algorithms used vary in detail, but most have a time step of one day. these are the primary tools available to assess the potential consequences of climate change on crop production and also provide proper knowledge of crop overall performance and yield gaps, genetic improvement , proper prediction of pest and insect outbreaks, more efficient irrigation , along with optimized planting dates.

Key words: Crop simulation model, Climate change,Yield gap, Dynamic models