Nitrogen watch archive

This page archives tracked spring rainfall and identified ‘danger areas’ that could have caused problems with N loss and deficiency in corn. This is a serious production and environmental problem that is estimated to have cost Midwestern corn producers 2 billion bushels total from 2008 to 2011.

To see current nitrogen watch content, visit nitrogen watch.

Nitrogen watch archive

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    Nitrogen watch 2019

    Nitrogen watch for well- and moderately well-drained soils

    Well-drained soils are vulnerable mainly to nitrogen loss from leaching. This process can start shortly after fertilizer application (with some delay for ammonia). We have used April 1 to represent a preplant N application date. For ammonia or for applications later than April 1, risk is lower; for applications before April 1, risk is higher.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 16 or more inches of rainfall from April 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 16 or more inches of rainfall since April 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Satellite images or canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    June 30
    June 23
    June 16
    June 9
    June 2
    May 26
    May 19

    Nitrogen watch for poorly- and somewhat poorly-drained soils

    Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive. My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 12 or more inches of rainfall since May 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Satellite images or canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    June 30
    June 23
    June 16
    June 9
    June 2
    May 26
    May 19
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    Nitrogen watch 2018

    Well-and moderately well-drained soils

    Well-drained soils are vulnerable mainly to nitrogen loss from leaching. This process can start shortly after fertilizer application (with some delay for ammonia). We have used April 1 to represent a preplant N application date. For ammonia or for applications later than April 1, risk is lower; for applications before April 1, risk is higher.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 16 or more inches of rainfall from April 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 16 or more inches of rainfall since April 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Midwest
    July 1
    June 24
    June 17
    June 10
    June 3
    May 27
    May 20
    May 13
    May 6
    April 29
    April 22

    Poorly- and somewhat poorly-drained soils

    Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive. My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 12 or more inches of rainfall since May 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Midwest
    July 1
    June 24
    June 17
    June 10
    June 3
    May 27
    May 20
    May 13
    May 6
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    Nitrogen watch 2017

    Well-and moderately well-drained soils

    Well-drained soils are vulnerable mainly to nitrogen loss from leaching. This process can start shortly after fertilizer application (with some delay for ammonia). We have used April 1 to represent a preplant N application date. For ammonia or for applications later than April 1, risk is lower; for applications before April 1, risk is higher.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 16 or more inches of rainfall from April 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 16 or more inches of rainfall since April 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    July 2     July 2
        July 2
    June 25     June 25
        June 25
    June 18     June 18
        June 18
    June 11     June 11
        June 11
    June 4     June 4
        June 4
    May 28     May 28
        May 28
    May 21     May 21
        May 21
    May 14     May 14
        May 14
    May 7     May 7
        May 7
    April 30     April 30
        April 30
    April 23     April 23
        April 23
    April 16     April 16
        April 16
    April 9     April 9
        April 9

    Poorly- and somewhat poorly-drained soils

    Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive. My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 12 or more inches of rainfall since May 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    July 2     July 2
        July 2
    June 25     June 25
        June 25
    June 18     June 18
        June 18
    June 11     June 11
        June 11
    June 4     June 4
        June 4
    May 28     May 28
        May 28
    May 21     May 21
        May 21
    May 14     May 14
        May 14
    May 7     May 7
        May 7
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    Nitrogen watch 2016

    Well-and moderately well-drained soils

    Well-drained soils are vulnerable mainly to nitrogen loss from leaching. This process can start shortly after fertilizer application (with some delay for ammonia). We have used April 1 to represent a preplant N application date. For ammonia or for applications later than April 1, risk is lower; for applications before April 1, risk is higher.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 16 or more inches of rainfall from April 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 16 or more inches of rainfall since April 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    July 3     July 3
        July 3
    June 26     June 26
        June 26
    June 19     June 19
        June 19
    June 12     June 12
        June 12
    June 5     June 5
        June 5
    May 29     May 29
        May 29
    May 22     May 22
        May 22
    May 15     May 15
        May 15
    May 8     May 8
        May 8

    Poorly- and somewhat poorly-drained soils

    Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive. My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 12 or more inches of rainfall since May 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    July 3     July 3
        July 3
    June 26     June 26
        June 26
    June 19     June 19
        June 19
    June 12     June 12
        June 12
    June 5     June 5
        June 5
    May 29     May 29
        May 29
    May 22     May 22
        May 22
    May 15     May 15
        May 15
    May 8     May 8
        May 8
  • Show/Hide

    Nitrogen watch 2015

    Nitrogen watch for well- and moderately well-drained soils

    Well-drained soils are vulnerable mainly to nitrogen loss from leaching. This process can start shortly after fertilizer application (with some delay for ammonia). We have used April 1 to represent a preplant N application date. For ammonia or for applications later than April 1, risk is lower; for applications before April 1, risk is higher.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 16 or more inches of rainfall from April 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 16 or more inches of rainfall since April 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    June 30     June 30
        June 30
    June 28     June 28
        June 28
    June 21     June 21
        June 21
    June 14     June 14
        June 14
    June 7     June 7
        June 7
    May 31     May 31
        May 31
    May 24     May 24
        May 24
    May 17     May 17
     
    May 10     May 10
     
    May 3     May 3
     
    April 26     April 26
     
    April 19     April 19
     

    Nitrogen watch for poorly- and somewhat poorly-drained soils

    Poorly-drained soils lose N mainly by denitrification, which is very temperature-sensitive. My rule of thumb is that wet conditions in May and June cause denitrification losses, but losses in April are minimal.

    Areas with diagonal shading are ‘danger areas’ that are on track to have 12 or more inches of rainfall from May 1 to June 30. This does not mean that significant loss of N has already happened, just that producers in these areas should be watchful and aware of the potential for N loss and deficiency.

    Areas shown in cross-hatch are ‘problem areas’ that have already received 12 or more inches of rainfall since May 1. I expect a majority of fields to have substantial yield loss due to N deficiency when all N was applied pre-plant. I suggest that producers look at their fields and when N stress is seen apply additional N. Rescue N applications are likely to be profitable until tasseling or later in fields with deficiency symptoms. Canopy sensors potentially provide a way to improve distribution of this N application, putting more N where stress is greatest and little or none where corn looks good.

    Missouri    Midwest   Contiguous USA
    June 30     June 30
        June 30
    June 28     June 28
        June 28
    June 21     June 21
        June 21
    June 14     June 14
        June 14
    June 7     June 7
        June 7
    May 31     May 31
        May 31
    May 24     May 24
        May 24
    May 17     May 17
     
    May 10     May 10
     
    May 3     May 3