Start Date

6-12-2001 12:00 AM

Description

Large amounts of commercial nitrogen fertilizer are applied to Iowa corn, and in other sections of the United States to additional crops such as wheat and cotton. Anhydrous ammonia is the most popular form of commercial nitrogen application. In preparation for the 1999 crop year, 1.4 billion pounds of nitrogen were applied as ammonia in Iowa and nine billion pounds were applied nationwide. Although crop rotation and manure utilization lessen the amount of off-farm purchased nitrogen, because of its low cost and existing distribution network, nitrogen in the form of anhydrous ammonia continues to be applied to many of Iowa's corn acres. The increasing cost of anhydrous ammonia has made effective and accurate application even more important to farmers. Physical properties of anhydrous ammonia cause it to convert from a high pressure liquid to a mixture of liquid and gas due to the decrease in pressure as it travels through application equipment. This liquid/gas mixture is very difficult to consistently distribute evenly to individual applicator knives across the swath width of the applicator. Perhaps because of these distribution problems, applicator operators tend to over apply nitrogen to compensate for these inherent problems. Individual case-study measurements of applicators have commonly found some individual knives to be applying three to four times the ammonia that other knives on the same applicator apply. Improving the uniformity of applicator distribution would give equipment operators more confidence that all plants were being equally fertilized and allow them to lower application rates.

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Dec 6th, 12:00 AM

Improving Anhydrous Ammonia Application Efficiency

Large amounts of commercial nitrogen fertilizer are applied to Iowa corn, and in other sections of the United States to additional crops such as wheat and cotton. Anhydrous ammonia is the most popular form of commercial nitrogen application. In preparation for the 1999 crop year, 1.4 billion pounds of nitrogen were applied as ammonia in Iowa and nine billion pounds were applied nationwide. Although crop rotation and manure utilization lessen the amount of off-farm purchased nitrogen, because of its low cost and existing distribution network, nitrogen in the form of anhydrous ammonia continues to be applied to many of Iowa's corn acres. The increasing cost of anhydrous ammonia has made effective and accurate application even more important to farmers. Physical properties of anhydrous ammonia cause it to convert from a high pressure liquid to a mixture of liquid and gas due to the decrease in pressure as it travels through application equipment. This liquid/gas mixture is very difficult to consistently distribute evenly to individual applicator knives across the swath width of the applicator. Perhaps because of these distribution problems, applicator operators tend to over apply nitrogen to compensate for these inherent problems. Individual case-study measurements of applicators have commonly found some individual knives to be applying three to four times the ammonia that other knives on the same applicator apply. Improving the uniformity of applicator distribution would give equipment operators more confidence that all plants were being equally fertilized and allow them to lower application rates.

 

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