Assessment of driving factors for yield and productivity developments in crop and cattle production as key to increasing sustainable biomass potentials

The sustainable production potential of biomass for energy and material purposes largely depends on the future availability of surplus agricultural lands made available through yield improvements in crop and livestock production. However, the rates at which yields may develop, and the influence of technological, economic and institutional factors on these growth rates are key uncertainties in assessing the potentials and impacts of biomass production. This study analyzes the pace and direction of historical yield developments (1961-2010) of five major crops, beef and cow milk in Australia, Brazil, China, India, USA, Zambia, and Zimbabwe, and examines the driving factors behind these developments. In addition, it explores how future yields are modeled and how modeling efforts may be improved. Average yield growth rates over the investigated period ranged in most cases between 0.7-1.6% year(-1) for crops, 1.0-1.5% year(-1) for milk, and 0.4-0.8% year(-1) for beef (relative to 2010). The role of different drivers is region specific. Yet, supporting agricultural policies have played an important role in increasing yields in all countries, especially for crops. In cattle production, a key factor was the importance of commercial beef and milk production for the national or export market. Based on regional differences in drivers and yield developments, models that assess biomass potentials and impacts should take into account regional drivers, yield gaps, and potential policy pathways.