%A WANG Hai-Yue,JIANG Ming-Jin,SUN Yong-Jian*,GUO Chang-Chun,YIN Yao-Zhu,HE Yan,YAN Tian-Rong,YANG Zhi-Yuan,XU Hui,MA Jun %T Effects of Conventional Urea Combined with Slow-release Urea Application on Phosphorus Uptake, Translocation and Distribution in Mechanically Transplanted Rice with Different Plant Spacings %0 Journal Article %D 2018 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2018.00115 %P 115-125 %V 44 %N 01 %U {https://zwxb.chinacrops.org/CN/abstract/article_6445.shtml} %8 2018-01-12 %X

Spilt-plot design with plant spacing (16, 18, and 20 cm with 30 cm-row spacing, respectively) as main plot and slow-release urea application rate (36, 66, 96, and 126 kg ha–1) combined with 54 kg ha–1 of conventional urea as subplot was arranged. In the present study P accumulated amount of rice plant at the main growth stages, P absorption and P uptake rate during various growth stages, P translocation amount of stem-sheath, and the P translocation rate and P conversion rate of leaf at the grain-filling stage were significantly affected by the slow-release urea application rate. Ninety-six kg ha–1 of slow-release urea combined with 54 kg ha–1 of conventional urea significantly improved P uptake, translocation and redistribution under the plant spacing of 18 cm, which is a best cultural practices for mechanically transplanted rice with the highest yield of 11 463.8 kg ha–1 in Southwest. A relatively high plant density (208.4 thousand plants per hectare) was established when the plant spacing was 16 cm. In addition, a higher total P accumulation amount of plant was achieved under 126 kg ha–1 of slow-release urea, resulting in improved P redistribution and high grain yield. The relatively lower plant density (166.7 thousand plants per hectare) was due to the larger plant spacing under the conditions of 20 cm-plant spacing and 126 kg ha–1 of slow-release urea. Although P accumulated amount decreased, P translocation from stem-sheath and leaf to panicle increased, resulting in increased P accumulation in panicle and grain yield. Furthermore, a relatively high correlation between P translocation amount (especially the P translocation amount of stem-sheath from heading stage to maturity stage) and grain yield (r = 0.72**) under a certain plant spacing combined with the slow-release urea, could be beneficial to improving grain yield.