The challenge of ensuring future food security is compounded by the ecological and resource threats intertwined with that of peak oil; …. climate change, population growth, projected peaks in other fuel sources (e.g., coal, natural gas, uranium), soil depletion and contamination, water shortages, and urbanization. 
Observers question whether low-input methods can produce sufficient food to feed the world’s growing population and achieve yields comparable to those of industrial agriculture. Numerous studies and United Nations (UN) reports suggest they probably can. 
A growing number of agribusiness executives, agricultural and ecological scientists, and international agriculture experts believe that a large-scale shift to organic farming or a new form of ‘agro-ecological farming’ would not only increase the world’s food supply, but might be the only way to eradicate hunger.
Additionally, the world’s longest study comparing organic and conventional farming (21 years) concluded that organic farming practices are more efficient, save energy, maintain biodiversity and keep soils healthy for future generations, when compared to conventional farming pract
The primary challenge for food security is to increase sustainable agricultural productivity at the national level to achieve greater food sovereignty. 
Food imports have to come by way of fossil fuel vehicles of one kind or another; ships or aeroplanes. As fossil fuels become more scarce and expensive that means that the food is going to become more expensive and the whole system will start to creak and groan around the edges. 
There are many potential benefits that result from the expected shift to lower-oil agriculture. Positive health effects may include reduced pesticide exposures, improved water quality, and reduced development of antimicrobial resistance. Petroleum use related to marketing, such as excess food packaging, will be trimmed. Price will eventually motivate consumers to eat less of those foods requiring the most oil to produce, process, and transport. These tend to be less-healthy options, so such a change could ultimately benefit the public’s health. 
People can lower dietary petroleum by eating lower on the food chain (industrial meat includes the embodied energy of both grain feed and animals), replace out-of-season produce with seasonal items whenever possible, avoid air-transported produce, and seek sustainably produced and regional foods transported in higher-efficiency vehicles. It is essential to minimize food waste and minimize mileage in car trips to stores and restaurants.
Perhaps the largest challenge is that few want to think about peak oil and other ecological threats such as climate change and soil depletion—never mind committing to precautionary change. Most of us prefer to continue the status quo, particularly if it has worked previously, if we have invested in it, and if it functions acceptably well. Change carries cost and risk. So, however, does inaction. 
The sooner we begin that transition to a new, low energy future, the easier the task will be. 
References: 1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3154242/
2. Richard Heinberg in ‘A Farm For the Future’ – the full length film on peak oil, farming & permaculture. Rebecca Hosking & Tim Green
4. Rebecca Hosking in ‘A Farm For the Future’ – the full length film on peak oil, farming & permaculture. Rebecca Hosking & Tim Green