Experimental Sites

We are monitoring 30 crop-management replicated treatments at 9 locations that cover major soil landform regions and climatic conditions in Iowa. Three of the six sites have tile drainage installations. Blue circles are locations with tile drainage and red circles are locations without tile drainage.

2017 experimental site map

Management information by treatment is provided in the table below

Number

Crop

Site

Treatment

Planting date

Cultivar maturity

Seeds/acre

N rate

(lbs N/acre)

Previous crop

1

Corn

Northwest

Early Planting

April 24

101-day

35,600

150

Soybean

2

Corn

Northwest

Late Planting

May 7

101-day

35,600

150

Soybean

3

Corn

North Central

0# N

May 5

101-day

35,000

0

Soybean

4

Corn

North Central

150# N

May 5

101-day

35,000

150

Soybean

5

Corn

North Central

300# N

May 5

101-day

35,000

300

Soybean

6

Corn

Northeast

Normal

May 8

101-day

35,000

 

Soybean

7

Corn

Central, Ames

Early

April 24

111-day

35,000

150

Soybean

8

Corn

Central, Ames

Late

May 15

111-day

35,000

150

Soybean

9

Corn

Central, Kelley

Normal

May 15

111-day

35,000

150

Soybean

10

Corn

Southwest

Early

April 13

115-day

34,000

150

Soybean

11

Corn

Southwest

Late

May 5

115-day

34,000

150

Soybean

12

Corn

South Central

0# N

April 25

115-day

35,000

0

Soybean

13

Corn

South Central

150# N

April 25

115-day

35,000

150

Soybean

14

Corn

South Central

300# N

April 25

115-day

35,000

300

Soybean

15

Corn

Southeast

Drainage

May 15

111-day

35,000

150

Soybean

16

Corn

Southeast

No drainage

May 15

111-day

35,000

150

Soybean

17

Corn

Southeast, Muscatine

Normal N

May 5

111-day

35,000

 

Soybean

18

Corn

Southeast,  Muscatine

Reduced N

May 5

111-day

35,000

 

Soybean

 

 

 

 

 

 

 

 

 

19

Soybean

Northwest

Early

May 8

2.2 MG

140,000

 

Corn

20

Soybean

Northwest

Late

 

2.2 MG

 

-

Corn

21

Soybean

North Central

Normal

May 9

2.2 MG

140,000

-

Corn

22

Soybean

Northeast

Normal

May 8

2.2 MG

190,000

-

Corn

23

Soybean

Central, Ames

Early

May 8

3.2 MG

140,000

-

Corn

24

Soybean

Central, Ames

Late

 

3.2 MG

 

-

Corn

25

Soybean

Central, Kelley

Normal

 

3.2 MG

 

-

Corn

26

Soybean

Southwest

Early

April 24

3.4 MG

160,000

-

Corn

27

Soybean

Southwest

Late

May 15

3.4 MG

160,000

-

Corn

28

Soybean

South Central

Normal

May 1

3.4 MG

140,000

-

Corn

29

Soybean

Southeast

Drainage

May 15

3.2 MG

140,000

-

Corn

30

Soybean

Southeast

No drainage

May 15

3.2 MG

140,000

-

Corn

Each system treatment is replicated three times. Within a plot we collect the measurements listed in the table below. Weather data are recorded hourly. Soil nitrogen data are taken twice per month at two depths from April to November. Soil water and temperature are monitored at multiple depths every 30 minutes. Crop data are collected eight times over the growing season. A portion of that data are provided in this website.

Weather Soil Crop
Temperature Water Staging
Radiation Groundwater Biomass production
Precipitation Temperature Biomass partitioning
Humidity Soil NO3 Leaf area index
Wind speed Soil NH4 Grain accumulation
  N20 emissions Tissue N concentration
  Tile drainage N-fixation
  NO3 leaching Root growth and depth