The relative contributions of changes in yield and land area to increasing crop output

Global average yields of the world's main food crops have increased over the past 50 years, and these yield increases have varied over time. For most crops, yields have grown significantly faster during periods of higher demand growth, and the contribution of yield growth to output growth has varied between crops. These variations reflect the range of measures available to growers to enhance yields of each crop, which are typically not fully deployed during periods of low demand growth and low relative price. This paper applies two methods using consistent, long‐term historic relationships to demonstrate that crop yield, area and price changes are not independent, and that area changes and yield changes in response to market signals are different for different crops and regions. One of these methods is used to show the expected percentages of exogenous estimates of overall demand growth that will be met by yield growth and by land use change for a range of biofuel crops. The estimated percentage of incremental output growth delivered by yield growth is 78% for EU cereals, with the remainder being met by area growth.     

Balancing food production and nature conservation in the Neotropical dry forests of northern Argentina

The growing human population and the increase in per capita food consumption are driving agriculture expansion and affecting natural ecosystems around the world. To balance increasing agriculture production and nature conservation, we must assess the efficiency of land‐use strategies. Soybean production, mainly exported to China and Europe, has become the major driver of deforestation in dry forest/savanna ecosystems of South America. In this article we compared land cover patterns (based on satellite imagery) and land‐use and human population trends (based on government statistics) in regions with two contrasting development pathways in the Chaco dry forests of northern Argentina, since the early 1970s. The area (ca. 13 million hectares) includes one of the largest continuous patches of tropical dry forests and has experienced rapid land‐use change. In the region where land use has been driven by government‐sponsored colonization programs, the expansion of extensive grazing has led to a growing rural population, low food production, and widespread environmental degradation. In contrast, in the region dominated by market‐driven soybean expansion, the rural population has decreased, food production is between 300% and 800% greater, and low‐density extensive cattle production has declined over extensive remaining forested areas, resulting in a land‐use trend that appears to better balance food production and nature conservation.