A single basal application of controlled-release coated urea to rice [Oryza sativa] cultures using pot seedlings in a cool region
1997
Sato, T. (Tohoku Univ., Sendai (Japan). Faculty of Agriculture) | Shibuya, K. | Saigusa, M.
A low-cost, high yielding culture of rice was studied by the application of controlled-release coated urea (CU) to pot seedlings (PS) - raised in a pot culture nursery box - cultivated in a cool region, and compared to the application of conventional fertilizer (CF) to pot seedling (PS) and mat seedlings (MS) - raised in a broadcast seeding nursery box. The plant length and the number of tillers per hill in the PS plots were longer and larger than those in the MS plots due to the superior characteristics of the seedlings. However, the number of tillers/centiare in the Ps plots was less than that in the MS plots. Reflecting the nitrogen released from the coated urea, the plant length and number of tillers/centiare in the PS-GU plots were inferior to those in the PS-CF and MS-CF plots at the early growth stage. However, after the neck node differentiation stage, these were reversed due to the increased release of nitrogen from the coated urea. As a result, the leaf color value and dry weight of the rice in the PS-CU plots were higher than those in the PS-CF and MS-CF plots. The yields of brown were in the following order: PS-Cu plot PS-CF plot MS-CF plot. The number of panicles and spikelets were larger in the PS-Cu plot than those in the PS-CF and MS-CF plots, which might affect the increased yield. It seems that the photosynthetic activity of the rice plants in the PS-CU plot was maintained at a high rate throughout the ripening stage. The nitrogen uptake and efficiency of the applied fertilizer were in following order: PS-Cu plot PS-CF plot MS-CF plot. The recovery of basal nitrogen in coated urea (63-68%) was much greater than that of ammonium sulfate (30-40%), and greater than the recovery of the top dressed nitrogen of ammonium sulfate (41-59%)
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