You are here

Mapping Out September Crop Progress in Iowa

September was soggy for Iowa corn and soybean farmers.

On trend with the 2019 growing season, September was a soggy month for Iowa corn and soybean farmers looking forward to harvest.

Here’s a five-week breakdown of the weather and how it affected corn and soybean progress throughout the Hawkeye state.

Week 1: September 1-7

The month started off with some dry and moderatly droughty areas in the state. On September 3, over 11% of the state was in moderate drought and 53.28% was abnomally dry.

Iowa drought monitor map for September 3, 2019
David Miskus

“A new month begins with outlooks indicating the possibility of wetter than normal conditions across the state,” said Iowa Secretary of Agriculture Mike Naig. “This follows a dryer-than-normal end to August.”

On September 1, 86% of the Iowa corn crop was at dough stage compared with a five-year average of 94%, according to the September 3 USDA Crop Progress report. Just 41% of the corn crop had dented compared with a five-year aveage of 64%. Only 1% of the corn crop was rated mature. At the same time a year ago, in 2018, 14% of Iowa corn was mature.

Iowa corn conditions were reported as follows:

  • Very poor: 3%
  • Poor: 8%
  • Fair: 27%
  • Good: 51%
  • Excellent: 11%

Soybean progress also lagged behind the average pace to start September. The first USDA Crop Progress report of the month said 98% of the soybean crop was blooming compared to a five-year average of 100%. Soybeans setting pods were at 90% compared with the 96% five-year average.

Iowa soybean conditions were reported as follows:

  • Very poor: 3%
  • Poor: 8%
  • Fair: 29%
  • Good: 51%
  • Excellent: 9%

By the end of the week, less than 1 inch of precipitation was recorded across the state.

Map of precipitation across Iowa September 1-7, 2019
Iowa Environmental Mesonet

Week 2: September 8-14

While some parts of Iowa got welcomed precipitation going into the second week of September, dry conditions persisted in many counties. More than 44% of the state was abnormally dry, and 9.68% of Iowa was in moderate drought to start the week.

Iowa drought monitor map for September 10, 2019
David Miskus

In his weekly crop update statement, Naig noted farmers had started to prepare equipment for harvest.

On September 8, 91% of the Iowa corn crop was at dough stage compared with a five-year average of 97%, according to the September 9 USDA Crop Progress report. Just 60% of the corn crop had dented compared with a five-year average of 79%. Only 4% of the corn crop was rated mature. At the same time a year ago, in 2018, 26% of Iowa corn was mature.

Iowa corn conditions were reported as follows:

  • Very poor: 3%
  • Poor: 8%
  • Fair: 26%
  • Good: 52%
  • Excellent: 11%

Soybean progress continued behind the average pace, too. The second USDA Crop Progress report of the month said 94% of the soybean crop was setting pods compared to a five-year average of 98%. 

Iowa soybean conditions were reported as follows:

  • Very poor: 3%
  • Poor: 8%
  • Fair: 28%
  • Good: 51%
  • Excellent: 10%

Above-average temperatures helped the late-planted corn mature, Naig said. In the southern part of Iowa temperatures more than 7°F. above average were recorded.

Iowa temperature departure map for second week in September
Iowa Environmental Mesonet

Most parts of the state benefited from an above-average number of growing degree days during the second week of September.

Iowa growing degree days departure map for week 2 of September 2019 from Iowa Environmental Mesonet
Iowa Environmental Mesonet

By Saturday of the second week, tremendous amounts of rain had fallen on Iowa farms. Totals peaked at 8.64 inches in the northeast part of the state.

Iowa-September-Week2-Precipitation-Map
Iowa Environmental Mesonet

Week 3: September 15-21

Heavy rains eased dry conditions in the northern and central parts of the state. The drought monitor map from September 17 indicates less than 5% of the state was in moderate drought, and abnormally dry acreage was reduced to 27.32% of the state.

Iowa drought monitor map for September 17, 2019
David Miskus

On September 15, 74% of the Iowa corn crop was dented compared with a five-year average of 89%, according to the September 16 USDA Crop Progress report. Only 8% of the corn crop was rated mature. At the same time a year ago, in 2018, 49% of Iowa corn was mature. The five-year average for the state is 34%. Although harvest had begun in other parts of the country, no corn had been harvested in Iowa as of September 15, the USDA said.

Iowa corn conditions were reported as follows:

  • Very poor: 2%
  • Poor: 7%
  • Fair: 26%
  • Good: 53%
  • Excellent: 12%

Soybean progress also lagged behind the average crop progress pace. The third USDA Crop Progress report of the month said 96% of the soybean crop was setting pods compared to a five-year average of 100%. Soybeans dropping leaves were at just 5% compared with the 29% five-year average.

Iowa soybean conditions were reported as follows:

  • Very poor: 2%
  • Poor: 6%
  • Fair: 29%
  • Good: 52%
  • Excellent: 11%

The third week of September brought more than an inch of rain to many Iowa counties. Precipitation totals approached 3.5 inches in a couple parts of the state.

Precipitation totals for Iowa week 3 of September 2019
Iowa Environmental Mesonet

Temperatures continued well above average across the state.

Temperature departure map from Iowa Environmental Mesonet for third week of September 2019
Iowa Environmental Mesonet

Another week of above average growing degree days boosted crop maturity progress.

Iowa growing degree days departure map for week 3 of September 2019
Iowa Environmental Mesonet

Week 4: September 22-28

Rain in the second and third weeks of September cleared up most of the drought conditions in the state by the release of the September 24 map in the fourth week. Just the southeast corner, accounting for 6.47% of the state, remained abnormally dry.

Iowa drought monitor map for September 24, 2019
David Miskus

On September 22, 82% of the Iowa corn crop was dented compared with a five-year average of 95%, according to the September 23 USDA Crop Progress report. Just 18% of the corn crop was rated mature. At the same time a year ago, in 2018, 71% of Iowa corn was mature. The five-year average for the state is 55%. Although harvest had begun in other parts of the country, no corn had been harvested in Iowa as of September 22, the USDA said. Last year on September 22, 5% of Iowa corn was harvested.

Iowa corn conditions were reported as follows:

  • Very poor: 2%
  • Poor: 7%
  • Fair: 26%
  • Good: 53%
  • Excellent: 12%

Soybeans in the state made progress toward maturity, but not enough to catch the five-year average pace. The fourth USDA Crop Progress report of the month said 22% of the soybean crop was dropping leaves compared to a five year average of 54%.

Iowa soybean conditions were reported as follows:

  • Very poor: 2%
  • Poor: 7%
  • Fair: 29%
  • Good: 51%
  • Excellent: 11%

Continued heavy rains, up to 6 inches, hit the southern third of Iowa in the fourth week of September.

Iowa precipitation map for week for of September 2019
Iowa Environmental Mesonet

Week 5: September 29-30

Naig declared harvest was officially under way in his September 30 crop update. “Today, Gov. Reynolds signed a proclamation that allows the transportation of oversize and overweight loads of grain for 60 days during the harvest season. This is a good reminder that we must all watch for slow moving vehicles on the roadways so everyone has a safe and productive harvest season,” he said.

On September 29, 90% of the Iowa corn crop was dented compared with a five-year average of 98%, according to the September 30 USDA Crop Progress report. Only 36% of the corn crop was rated mature. At the same time a year ago, in 2018, 86% of Iowa corn was mature. The five-year average for the state is 74%. Iowa farmers have harvested 2% of the state’s corn crop, the USDA said.

Iowa corn conditions were reported as follows:

  • Very poor: 2%
  • Poor: 7%
  • Fair: 26%
  • Good: 54%
  • Excellent: 11%

Soybeans in Iowa continue to mauture behind the five-year average pace. The fifth USDA Crop Progress report of the month said 49% of the soybean crop was dropping leaves compared with a five-year average of 77%. Farmers in the state started harvesting soybeans. USDA reported soybean harvest is 3% complete, 9% behind the five-year average harvest pace.

Iowa soybean conditions were reported as follows:

  • Very poor: 2%
  • Poor: 7%
  • Fair: 28%
  • Good: 52%
  • Excellent: 11%

The month of September ended on a soggy note with more than 1.5 inches of rain in many southern and eastern Iowa counties in the final days of the month.

Iowa precipitation totals for week five of September 2019
Iowa Environmental Mesonet

September 2019 Overview

All in all, September in Iowa was wet and warm.

Iowa-September-2019-Precipitation-Total
Iowa Environmental Mesonet

Some parts of the state recorded more than 300% of their average September rainfall.

Iowa precipitation percent map September 2019
Iowa Environmental Mesonet

Said another way, parts of the state got more than 11 inches of rain above average during the month of September.

map of iowa precipitation
Iowa Environmental Mesonet

Warmer-than-average temperatures of 4°F. or more were recorded across the state.

Average temperature map Iowa September
Iowa Environmental Mesonet

Across the state crops got more growing degree days in September than average.

GDD Map of Departures for iowa
Iowa Environmental Mesonet

Read more about

Tip of the Day

Agronomy Tip: Strategize Weed Control to Prepare for 2020

Soybeans in a no-till field. Target weeds this fall on corn fields that will be no-till soybean acres next spring.

Talk in Marketing

Most Recent Poll

How is your harvest progress?