CEDAR BASIN CROP CONSULTING

Spring 1999 NEWSLETTER

Shannon Gomes

Included in this issue: Nitrogen Management, Starter Fertilizer and GMO Corn Unapproved Individual Company Hybrid Numbers

NITROGEN MANAGEMENT

There has been some concern on the fate of fall applied nitrogen. Conditions for 1999 have favored greater chances of nitrogen loss.

[Figure 1]

TOTAL PERCENTAGE OF REMAINING N (NH4 &endash; N + NO3) FOR AN AVERAGE YEAR

NH4-N APPLICATION DATE: November 10, 1998

SOIL SERIES: 398

COUNTY: Bremer

Long-Term Average on

With N-Serve

Without N-Serve

May 1, 1999

86%

73%

June 1, 1999

80%

53%

July 1, 1999

72%

53%

 

This table shows the fate of fall applied (November 10, 1998) nitrogen on a poorly drained soil (Tripoli). Without a nitrogen stabilizer (N-Serve) we stand to loose 27% of applied nitrogen and by June 1, only 53% is left. If you have fall applied nitrogen I recommend we monitor those fields with late spring nitrate test and aerial photos of fields. This year Cedar Basin Crop Consulting, Inc. will have the capacity to monitor fields with aerial remote sensed flights (color and infrared photos) utilizing an ultra-lite (with Gomes as the pilot).

 

STARTER FERTILIZER

For years starter response has been inconsistent. Although we have seen physical color differences, it did not always translate to higher yields. Well now perhaps we have some valid research from University of Wisconsin. Dr. Larry Bundy finished a three-year study on soils with high Phosphorus and Potassium levels.

Their research revealed that planting date and relative maturity, not soil temperature, were major factors in yield response. Late planted and full season hybrids showed greatest response.

They developed a 240 Rule of Thumb, adding planting date (counting from January 1, and relative maturity (PD + RM > 240) has greatest chance of economic response to starter.

[Figure 2]

Measure the Economic Return of Starter Fertilizer

Planting Date

April 25

May 2

May 5

May 10

May 15

May 20

May 25

May 30

Corn Relative Maturity (In Days)

Percent Probability of Positive Economic Return

90

10

15

20

25

30

35

40

45

95

15

20

25

30

35

40

45

50

100

20

25

30

35

40

45

50

55

110

30

35

40

45

50

55

60

65

 

A COMBINATION of corn's relative maturity and planting date is an excellent way to predict economic returns to starter fertilizer, according to a Wisconsin study. It found planting date and relative hybrid maturity are major factors affecting corn yield response to starter.

20 (_ FARM JOURNAL/MID-FEBRUARY 1999

Another important find was that soil potassium levels and not phosphorus levels had significant response to starter. Potassium soil test levels below 140 PPM had more frequent response.

 GMO (GENETICALLY MODIFIED ORGANISMS)

As if we need something else this spring to be concerned about, now major grain merchandisers, ADM and Cargill, are refusing to take certain GMO hybrids. Basically it appears that Roundup Ready corn and certain Liberty Link/BT hybrids will not be accepted (due to European resistance). The enclosed list of unapproved hybrids was sent to me by DeKalb. I recommend either switch to approved hybrids or plan to segregate those fields. Novartis' 4242BT and 4640BT are approved even though they are Liberty Link/BT. If you have internet access go to NCGA website http://www.ncga.com or http://www.pioneer.com for more information.