Spring weather conditions in Iowa typically leave a small window for ideal planting conditions. Iowa farmers are able to make significant planting progress in a short amount of time when the conditions are right. For example, in 1992, 64% of the Iowa corn crop was planted in one week. Again in 2011, corn planting progress completed during one week exceeded 60%. It is fairly common for more than 40% of corn acres to be planted within a week - during 15 out of the last 28 years, 40% or more of the Iowa corn crop has been planted in one week’s time.

How does harvest progress compare? The following graphs show the single largest week of harvest progress during each year from 1990-2017. In Iowa, the two largest weeks for harvest progress were in 1993 and 2013, when 30% of Iowa’s corn crop was harvested in one week. Since 1990, every year has had a week where at least 15% of the Iowa corn crop was harvested, and 23 out of those 28 years have had a week with 20% or more harvested in one week’s worth of time.

On a national level, the two highest years for corn harvest progress completed in one week were also in 2013 and 1993 at 27% and 23%, respectively.


The weeks with the highest average corn harvest progress from 1990 to 2017 in Iowa are Week #42 and Week #43 (mid to late October) with about 17%, on average, harvested during each of those weeks. On a national level, the average corn harvest progress by week is higher than Iowa early on in the season, but is lower than Iowa during October.

When looking at historical soybean planting progress, Iowa harvested 65% of soybean acres within one week in 2013, and 49% in both 2011 and 1997.

On a national level, the largest year for soybean harvest completed during one week was in 2013 with 52% harvested. This was by far the largest week with the next highest occurring in 2011 with 32% harvested during one week.

The week with the highest average soybean harvest progress from 1990 to 2017 in Iowa is Week #40 (early October), with almost 27%, on average, harvested during that week. The average soybean harvest progress by week is higher in Iowa than the U.S. early on during the harvest season from Week #38 to Week #42.

This information is also important on an individual farm level when determining machinery capacities. Is your farm operation properly equipped to plant or harvest during a short window of ideal weather conditions, or are you overpaying for unnecessary machinery capacity?

Michelle Mensing, Research Analyst, Decision Innovation Solutions (DIS). DIS is an Iowa-based economic research firm which provides regular farm economic research for Iowa Farm Bureau staff & members.