View article

The increase in annually cropped area that has occurred in the eastern Pampas of South America (Uruguay) since 2002 was largely achieved by converting crop-pasture rotations to continuous annual no-till cropping systems. We studied the impact of this intensification on the attainable wheat yield (Yatt) and the yield gap (Yg), with the latter defined as the difference between Yatt and actual yield (Ya). Our measure of agricultural intensification is the length in years of continuous cropping (YCC). We computed both Yatt and Yg from 1072 wheat yield records obtained from producers between 2009 and 2012. The database included grain yield, agro-climatic region, preceding crop, sowing date, cultivar, nitrogen (N) fertilization rate and YCC. For each field, we calculated a climatological index (CI) that combines temperature, radiation and precipitation during both the spike and grain growth phases. To estimate Yatt, we …