Nitrogen

Don't double dip soybean

jvandyk — Fri, 16 Nov 2007 16:23:00 -0600

Includes rate guidelines for different nitrogen and grain prices.

Economic Optimum N Rate Differences

jvandyk — Fri, 16 Nov 2007 16:20:15 -0600

Difference in economic optimum N rate for continuous corn compared to corn rotated after soybean for seven sites in Iowa, 2000–2006 (J. E. Sawyer and D. W. Barker, Department of Agronomy, Iowa State University).

Carbon and nitrogen cycling with corn biomass harvest

jvandyk — Fri, 10 Aug 2007 13:25:31 -0500

What happens to soil carbon and nitrogen with stover removal?

Carbon and nitrogen cycling with corn biomass harvest

jvandyk — Fri, 10 Aug 2007 13:25:31 -0500

What happens to soil carbon and nitrogen with stover removal?

Carbon and nitrogen cycling with corn biomass harvest

jvandyk — Fri, 10 Aug 2007 13:25:31 -0500

What happens to soil carbon and nitrogen with stover removal?

Nitrogen loss: How does it happen?

jvandyk — Thu, 17 May 2007 13:06:52 -0500

What increases the potential for loss?

Yellowing from wet soils and nitrogen deficiency

jvandyk — Thu, 17 May 2007 13:00:36 -0500

Field areas with ponded water showing corn yellowing from wet soils and N deficiency. (John Sawyer)

Estimating nitrogen losses -- early spring 2007

jvandyk — Thu, 17 May 2007 12:53:27 -0500

How to come up with a meaningful estimate of nitrogen loss.

Estimating nitrogen losses -- early spring 2007

jvandyk — Thu, 17 May 2007 12:53:27 -0500

How to come up with a meaningful estimate of nitrogen loss.

Measuring the nitrogen status -- 2007

jvandyk — Thu, 17 May 2007 12:46:39 -0500

Two site-specific tests are presented.

Chlorophyll meter

jvandyk — Thu, 17 May 2007 12:35:08 -0500

A chlorophyll meter is used to collect readings in corn. (John Sawyer)

Chlorophyll meter values and N-rate deviation from optimum rate

jvandyk — Thu, 17 May 2007 12:33:00 -0500

Relationship between relative chlorophyll meter values and the N-rate deviation from the economic optimum N rate.

Field of N-deficient corn

jvandyk — Thu, 17 May 2007 12:04:09 -0500

A field of N-deficient corn and well-fertilized, non-N limiting strips. (John Lundvall)

Corn response to supplemental nitrogen

jvandyk — Thu, 17 May 2007 11:30:10 -0500

John Sawyer presents your nitrogen options.

Nitrogren being sidedressed

jvandyk — Thu, 17 May 2007 11:08:43 -0500

N being sidedressed. (John Lundvall)

High clearance N application

jvandyk — Thu, 17 May 2007 11:07:16 -0500

Supplemental N being applied with high clearance equipment. (John Lundvall)

Corn Nitrogen Rate Calculator Web tool update

jvandyk — Fri, 13 Apr 2007 15:45:57 -0500

Twenty-seven additional response trials added.

Increasing the frequency of corn in crop sequences: Grain yield and response to nitrogen -- a research update

jvandyk — Tue, 13 Feb 2007 16:07:25 -0600

Research results are presented.

Increasing the frequency of corn in crop sequences: Grain yield and response to nitrogen -- a research update

jvandyk — Tue, 13 Feb 2007 16:07:25 -0600

Research results are presented.

Increasing the frequency of corn in crop sequences: Grain yield and response to nitrogen -- a research update

jvandyk — Tue, 13 Feb 2007 16:07:25 -0600

Research results are presented.

Effect of rotation and N rate on average corn yield

jvandyk — Tue, 13 Feb 2007 15:59:20 -0600

Rotation and N rate effects on average corn yield from 1979 to 2004. An upper case letter in the rotation code indicates the sequence in the rotation for the corn crop to which the graphed yield refers. For example, c-c-C-s indicates third-year corn of the corn-corn-corn-soybean rotation.

Effect of rotation and N rate on average corn yield

jvandyk — Tue, 13 Feb 2007 15:59:20 -0600

Effects of rotation and N fertilization on corn yield

jvandyk — Tue, 13 Feb 2007 15:57:47 -0600

Rotation and N fertilization effects on corn yield over time (averages for two groups of sequences shown in Figure 1).

Effects of rotation and N fertilization on corn yield

jvandyk — Tue, 13 Feb 2007 15:57:47 -0600

Rotation and N fertilization effects on corn yield over time (averages for two groups of sequences shown in Figure 1).

Nitrogen fertilization for corn following corn

jvandyk — Mon, 12 Feb 2007 14:40:02 -0600

Soybean rotation results in greater crop-available nitrogen.

Yield response to N with continuous corn vs. rotation

jvandyk — Mon, 12 Feb 2007 14:27:04 -0600

Corn grain yield response to fertilizer N application with continuous corn (CC) and corn following soybean (SC) at seven ISU research farms from 2000 to 2006 (EONR is the economic optimum N rate, determined at a 0.10 price ratio).

Corn Nitrogen Rate Calculator Web tool updated

jvandyk — Tue, 19 Sep 2006 15:56:28 -0500

Links to handy resources.

New publication offers rationale for nitrogen use in corn production

jvandyk — Wed, 02 Aug 2006 15:46:31 -0500

Publication covers the entire region.

The Illinois Soil Nitrogen Test: Should it be used in Iowa?

jvandyk — Thu, 13 Oct 2005 10:54:19 -0500

John Sawyer and Ali Tabatabai explore this question.

Checking corn nitrogen status

adminn — Thu, 02 Jun 2005 16:39:41 -0500

Chlorophyll readings can aid in confirming suspected N-loss situations.

High prices and tight supply make fertilization decisions tough

jvandyk — Sun, 03 Oct 2004 14:00:00 -0500

John Sawyer presents some options.

Assessing nitrogen losses

jvandyk — Sun, 06 Jun 2004 14:00:00 -0500

How to use chlorophyll readings.

Nitrogen losses after the heavy rains

jvandyk — Sun, 06 Jun 2004 14:00:00 -0500

Off-color corn may not mean a nitrogen shortage.

Soybean seed inoculation

jvandyk — Sun, 20 Apr 2003 14:00:00 -0500

Rhizobium bacteria must be present in the soil.

Getting the most from nitrogen fertilizer dollars

jvandyk — Sun, 13 Apr 2003 14:00:00 -0500

What management options are best?

Natural gas prices impact nitrogen fertilizer costs

jvandyk — Sun, 13 Apr 2003 14:00:00 -0500

Price spike leads to high N costs.

Pay attention to management needs of fertilizer products

jvandyk — Sun, 13 Apr 2003 14:00:00 -0500

Each fertilizer has different management considerations.

Residue management and manure application