Rice Response to Nitrogen Fertilization under Stale Seedbed and Conventional Tillage Systems
- D. L. Harrell *a,
- B. S. Tubañab,
- J. Loftonb and
- Y. Kankeb
- a Louisiana State Univ. Agric. Cent. Rice Res. Stn., 1373 Caffey Rd., Rayne, LA 70578
b School of Plant, Environ. and Soil Sci., Louisiana State Univ. Agric. Cent., 104 Sturgis Hall, Baton Rouge, LA 70803. Published with the approval of the Director of the Louisiana Agric. Exp. Stn. as publication no. 2010-266-5133. This research was funded in part by the Louisiana Rice Res. Board
Drill-seeded, delayed-flood rice (Oryza sativa L.) using fall-stale seedbed (FSS) tillage has risen in popularity over the past decade in the southern USA. Nitrogen research in rice has historically focused on conventional tillage (CT). The objective of the current study was to evaluate potential differences in agronomic characteristics, optimal N rate, N uptake, and N fertilizer recovery efficiency (RE) between the FSS and CT rice production systems. Two varieties (‘Catahoula’ and ‘Neptune’), two tillage systems (CT and FSS), and nine N rates (0, 34, 67, 101, 134, 168, 202, 235, and 269 kg ha−1) were evaluated. Rice emerged 4 d earlier and reached 50% heading 2 d later in CT as compared with the FSS; however, grain moisture at harvest was only slightly different between CT (169 kg ha−1) and the FSS (163 kg ha−1). Grain yield was 317 kg ha−1 higher in the FSS as compared with CT. The rate of fertilizer N needed to achieve maximum yield as determined by the linear-plateau model was 157 and 151 kg ha−1 for the FSS and CT, respectively. Nitrogen RE ranged from 54 to 63% across N rates but was not significantly affected by variety, tillage, N rate, or their interactions. These results validate current state university N recommendations for drill-seeded, delayed-flood rice production and suggest that N fertilizer recommendations should not be altered for rice grown using a FSS.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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