Farmer skills are also important to adapt production as consumer demand patterns shift away from traditional grains with rising household incomes. The Food and Agriculture Organisation of the United Nations (FAO) defines food security as the ideal in which all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life. The task may be particularly challenging in China: it has around 20% of the global population with just 10% of the world's agricultural land and below average water resources per capita.