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Effect of a Urease Inhibitor Phenyl Phosphorodiamidate on the Efficiency of Urea Applied to Rice

1983; Wiley; Volume: 47; Issue: 2 Linguagem: Inglês

10.2136/sssaj1983.03615995004700020020x

1435-0661

B. H. Byrnes, N. K. Savant, E. T. Craswell,

Plant nutrient uptake and metabolism

Soil Science Society of America JournalVolume 47, Issue 2 p. 270-274 Division S-4—Soil Fertility and Plant Nutrition Effect of a Urease Inhibitor Phenyl Phosphorodiamidate on the Efficiency of Urea Applied to Rice† B. H. Byrnes, B. H. ByrnesSearch for more papers by this authorN. K. Savant, N. K. SavantSearch for more papers by this authorE. T. Craswell, E. T. Craswell Research Associate, Soil Chemist, and Soil Scientist, respectively.Search for more papers by this author B. H. Byrnes, B. H. ByrnesSearch for more papers by this authorN. K. Savant, N. K. SavantSearch for more papers by this authorE. T. Craswell, E. T. Craswell Research Associate, Soil Chemist, and Soil Scientist, respectively.Search for more papers by this author First published: 01 March 1983 https://doi.org/10.2136/sssaj1983.03615995004700020020xCitations: 48 ‡ Contribution from Agro-Economic and Fertilizer Technology Divisions, International Fertilizer Development Center, P.O. Box 2040, Muscle Shoals, AL 35660. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Urea, the major source of nitrogen for rice, is subject to extensive ammonia volatilization losses when broadcast on flooded soils. As part of a program to modify and improve urea, the effect of the urease inhibitor phenyl phosphorodiamidate (PPD) on the efficiency of broadcast urea for wetland rice (Oryza sativa L.) was studied in the greenhouse using 15N. Addition of PPD to urea (5% wt/wt) increased plant recovery of 15N applied as basal broadcast and incorporated urea by 10 to 15% and reduced losses by 20% in absolute terms. Addition of PPD to urea topdressed at maximum tillering (30 d after transplanting) increased 15N plant recovery from 41 (without PPD) to 67% (with PPD) and decreased losses from 23 to 0% of the 15N applied. Despite these improvements in N efficiency, the addition of PPD reduced dry matter production under the particular conditions of the experiment. The effect of PPD on NH3 volatilization was then studied using 15N-labeled urea added to flooded soils placed in forced-draft systems in the absence of plants. Phenyl phosphorodiamidate addition reduced NH3 volatilization losses from 31% (without PPD) to < 5% (with PPD) of the 15N added. A rate of 1% PPD was as effective as 5% in delaying urea hydrolysis, maintaining a lower pH in the floodwater, reducing NH3 concentrations in the floodwater, and decreasing NH3 volatilization losses. In short-term (16 h) incubation studies, as little as 0.5% PPD in urea or 4 ppm PPD dissolved in the floodwater effectively blocked urea hydrolysis. These results indicate that the concept of using urease inhibitors to reduce losses and improve urea efficiency may have potential for wetland rice. Citing Literature Volume47, Issue2March-April 1983Pages 270-274 RelatedInformation