Comparison of Corn and Soybean Yields in the United States: Historical Trends and Future Prospects

Abstract

Developing successful strategies to ensure future increases in crop yield depends, in part, on a better understanding of the basis for past increases. To this end, I compared historical yield trends of two dissimilar crops—corn (Zea mays L.), a high yielding C4 grass, and soybean [Glycine max (L.) Merr.], a moderate yielding C3 legume—in high (Iowa, Illinois, Indiana) and low (Kentucky, Missouri, Tennessee) yield environments. Average state corn yield changed very little from 1866 to 1930, an era of low‐input agriculture, but it increased rapidly from 1950 to 2005 in all states as the low‐input system gave way to a high‐input system that utilized commercial hybrids, manufactured N fertilizer, herbicides, and higher plant populations. Soybean yield, first available in 1924, increased steadily from the beginning until 2005. Corn yield increased faster than soybean yield in the early decades of the high‐input era (mean growth rates of corn were 3.3 vs. 1.5% per year for soybean with a slight advantage for both crops in high yield states) in all six states, but for the rest of the era (up to 40 yr), corn and soybean yields grew at nearly the same rate (1.8% per year for corn, 1.4% per year for soybean with a slight advantage for the low‐yield states). Thus, the efforts to improve the plant (plant breeding) and production environment (better management practices) had essentially the same affect on these two very dissimilar crops.

Crop physiology: A perspective for southern Africa

“…This balance appears to have been nearly exploited to the limit. Therefore, as the production potential of crops comes closer to the biological potential, it will become even more difficult to achieve the incremental improvement in agronomic productivity that we have seen in the past decades (Egli, 2008). Also, there is very little further potential to be exploited in raising whole-crop photosynthetic potential, as the photo-assimilation potential is capped by the photosynthetic pathways, and optimization of canopy display has also been almost fully exploited in the most productive crops.…”

Identifying Factors Controlling the Continuous Corn Yield Penalty

“…As a C 4 plant, corn is well adapted for growth in high-light, high-heat environments, allowing greater grain production from corn than the other major U.S. commodity crops under the climatic conditions of the country's most agriculturally productive region, the Midwest. For example, typical yields for soybean, the second most commonly grown crop in the United States, are only 28 to 34% of corn yields (Egli, 2008;National Agricultural Statistics Service, 2012). Corn is versatile in terms of its use potential; both grain and stover are used for animal feed and show promise as bioenergy feedstocks.…”

Productivity of different patterns for maize and forage millet intercropping under periodical cutting systems

“…Increases in DMER showed the more efficient use of land in additive intercropping, compared with replacement intercropping or maize grown alone. These results reflected the ability of maize/millet intercropping in additive patterns to better utilize growth resources than growing the two intercrops in replacement patterns (Blair et al, 2006;Egli, 2008 andBrintha &Seran, 2009). However, DMER values of more than one might be due to increases in plant population densities with better use in growth resources in additive than in replacement intercropping (Midya et al, 2005).…”