摘要 : This research evaluated differences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and ... 展开 This research evaluated differences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no-till. Results indicated that mean yields for sorghum [<i>Sorghum bicolor</i> (L.) Moench] and wheat (<i>Triticum aestivum</i> L.) with no-till were greater than with tillage. In addition, no-till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no-till on loamy soils. With the exception of corn (<i>Zea mays</i> L.) and cotton (<i>Gossypium hirsutum</i> L.) in the Southern Seaboard region, no-till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no-till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [<i>Glycine max</i> (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no-till had larger downside yield risks than when produced with no-till on loamy soils. The key findings of this study support the hypothesis that soil and climate factors impact no-till yields relative to tillage yields and may be an important factor influencing risk and expected return and the adoption of the practice by farmers.Digital Object Identifier http://dx.doi.org/10.2134/agronj2011.0291 收起