ABSTRACT
This chapter aims to characterize the long term variability and trends in grain crop production in North America. On a worldwide basis the major portion of the food energy consumed by Man comes from the cereal grains and oil seed crops, commonly known as the commodity trade grains. Since about 90% of the commodity trade grain crops in North America are produced under dryland cultural practices, seasonal weather and climatic fluctuations bring about most of the annual variability in production. In every measure of variability during the sample periods, the US soybean crop is the lowest, thus making it the most reliable crop from a national annual production viewpoint, among these major commodity grain crops. The annual production of US wheat has the lowest variability among the cereal grains in North America. This low variability is particularly striking when the US crop is compared to the Canadian wheat crop.
