The 2012 ASHS Annual Conference

A survey of plant nutrient use and removal was compiled within a GIS for each county in the United States.  The on-line tool (nugis.ipni.net) shows the partial nutrient balance derived from data on fertilizer use, animal manure, and nitrogen fixation.  This was compared with nutrient removed in harvested crops.  The search parameters are selected by the user (the nutrient, time period, geographic region) and interactive maps are produced.  Data is also available in tabular form. In order to make consistent comparisons across space and time, we selected years for our analysis where data were available from each source with some degree of consistency in reporting.  Data was obtained for five-year periods, coinciding with the USDA Census of Agriculture from 1987–2007.  The nutrient input, removal, and acreage values calculated for the portions of each county were summed by watershed to produce input, removal, and acreage data at the watershed scale. Nutrient Balances, Removal to Use Ratios, and Balances per Cropland Acre were then recalculated using this watershed scale data.  This partial nutrient balance does not account for atmospheric deposition, biosolids application, or nutrients contained in irrigation water.  It does not account for nutrient losses other than crop removal (such as leaching, erosion, or volatilization).  This tool allows the user to select regions of the United States that are of particular interest.  A national view reveals that nutrient “Removal to Use” ratios appear unsustainably high in some regions and unsustainably low in others.  It highlights the need for more intensive monitoring of soil nutrients and improved nutrient management.A survey of plant nutrient use and removal was compiled within a GIS for each county in the United States.  The on-line tool (nugis.ipni.net) shows the partial nutrient balance derived from data on fertilizer use, animal manure, and nitrogen fixation.  This was compared with nutrient removed in harvested crops.  The search parameters are selected by the user (the nutrient, time period, geographic region) and interactive maps are produced.  Data is also available in tabular form.

 In order to make consistent comparisons across space and time, we selected years for our analysis where data were available from each source with some degree of consistency in reporting.  Data was obtained for five-year periods, coinciding with the USDA Census of Agriculture from 1987 - 2007. 

 The nutrient input, removal, and acreage values calculated for the portions of each county were summed by watershed to produce input, removal, and acreage data at the watershed scale. Nutrient Balances, Removal to Use Ratios, and Balances per Cropland Acre were then recalculated using this watershed scale data.  This partial nutrient balance does not account for atmospheric deposition, biosolids application, or nutrients contained in irrigation water.  It does not account for nutrient losses other than crop removal (such as leaching, erosion, or volatilization). 

 This tool allows the user to select regions of the U.S. that are of particular interest.  A national view reveals that nutrient “Removal to Use” ratios appear unsustainably high in some regions and unsustainably low in others.  It highlights the need for more intensive monitoring of soil nutrients and improved nutrient management.