Influence of Agrotain, Ammonium Sulfate, and Urea on Ammonia Volatilization and Grain Yield of Delayed Flood Rice. (4927)
Authors:
R.J. Norman* - University of Arkansas
J.T. Bushong - University of Arkansas, Fayetteville C.E. Wilson, Jr. - University of Arkansas, Fayetteville D.L. Boothe - University of Arkansas, Fayetteville B.R. Griggs - University of Arkansas, Fayetteville W.J. Ross - University of Arkansas, Fayetteville N.A. Slaton - University of Arkansas, Fayetteville
Abstract:
The preflood nitrogen (N) fertilizer sets the yield potential of the rice cultivars grown in U.S. rice production and thus, its management is critical to obtaining profitable rice grain yields. The objectives of this study were to evaluate the ammonia volatilization loss and impact on rice yield when urea, Agrotain® and ammonium sulfate were applied preflood and a flood established at 1, 5 and 10 days after N application. Fifteen to 20% of the urea-N, only 3 to 5% of the ammonium sulfate-N, and only 2 to 3% of the Agrotain®-N was lost via ammonia volatilization within 5 days of application. By 10 days after application and time of flooding, the losses from ammonia volatilization where leveling off at about 17 to 25% for the urea, 4 to 10% for the Agrotain® and 3 to 5% for the ammonium sulfate. When flooding was delayed for 5 and 10 days after N fertilizer application, Agrotain®
and ammonium sulfate produced the highest grain yields which were quite similar and significantly higher than those produced with urea. Rice grain yields did not decline or declined only slightly as N fertilizer application time before flooding increased to 5 and 10 days when Agrotain® or ammonium sulfate were applied. If more than 2 to 3 days is required to move the flood water completely across a rice field after the preflood N fertilizer has been applied than an N fertilizer such as Agrotain® or ammonium sulfate should be used.
Speaker Information: Richard Norman, University of Arkansas, University of Arkansas, Dept of CSES,, Fayetteville, AR 72701; Phone: (479)575-5738; E-mail:
Session Information: Monday, November 1, 2004, 10:00 AM-12:00 PM Presentation Start: 10:00 AM (Poster Board Number: 2246)
Keywords: ammonia volatilization; nitrogen uptake; agrotain, ammonium sulfate, urea;
rice
