[Water requirement of paddy field under different soil water conditions].
Field experiment with three irrigation treatments, i.e., continuous flooding irrigation (CSF), moisture condition irrigation (MTC), and intermittent irrigation (IT) were installed to study the water requirement of paddy fields. The results showed that in field experiment, the evapotranspiration(ET) was 889.1, 635.9 and 775.9 mm, and the evapotranspiration rate was 6.9, 4.9 and 6.0 mm.d-1 for CSF, MTC and IT, respectively during the entire growing season. MTC and IT were less than CSF by 28.5 and 12.7%. Under sufficient water supply, the evapotranspiration calculation by Penman formula was less than that from field experiment by 29.3%, during stages from returning green to milk. The biomass was 16438.22, 15887.94 and 15757.88 kg.hm-2, and the grain yield was 8014.01, 7828.91 and 7853.93 kg.hm-2 for CSF, MTC and IT, respectively. No significant differences were found among three treatments. The water use efficiency (WUE) was 9.01, 12.31 and 10.12 kg.hm-2.mm-1 for CSF, MTC and IT, respectively. The WUE of MTC and IT were higher than that of CSF by 26.8 and 11.0%, showing that MTC was a comparatively water-saving irrigation treatment.
Wang
Xiaoying
X
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. wangxy0618@yahoo.com.cn
Wen
Dazhong
D
Liang
Wenju
W
D017753:Ecosystem; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism; D018526:Plant Transpiration; D011891:Rain; D012987:Soil; D014867:Water / Q000378:metabolism*
D012987:Soil; D014867:Water