Physiological characterization of rice grown under different water management systems
2002
Cao, W. X. | Jiang, D. | Wang, S. H. | Tian, Y. C.
In a cement-box experiment in Nanjing (China), production characteristics, water-use efficiency, nitrogen-use efficiency, and the major physiological characteristics of three alternative water management practices - the System of Rice Intensification (SRI), plastic ground-cover system (PGS), and intermittent irrigation system (IIS) - were compared with a conventional flooded rice system (CK). In addition, the effect of two nitrogen levels (150 and 300 kg ha-1) was studied. Water supply in SRI and IIS was 46% and 36% lower than in CK, respectively, whereas their yields were similar or significantly higher, 5% (SRI at 150 kg N ha-1) and 8% (IIS at 300 kg N ha-1), resulting in greater water-use efficiency and nitrogen-use efficiency. The higher yields of SRI and IIS compared with CK were associated with higher harvest indices but not with differences in total biomass production. Water supply and yield in PGS were 65% and 62% lower than in CK, respectively. At jointing stage, leaf photosynthesis, transpiration rate, and stomatal conductance decreased with reduced water input. High nitrogen levels increased leaf photosynthesis and transpiration rate in IIS, SRI, and PGS more than in CK. At heading, leaf-soluble sugar, nonprotein nitrogen content, and nitrate reductase activity were higher in IIS, SRI, and PGS than in CK. Nitrogen uptake in SRI and IIS was similar to that in CK, but nitrogen redistribution from the vegetative organs to grain was larger than that in CK. High nitrogen levels increased water-use efficiency and decreased nitrogen-use efficiency in all water treatments.
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Эту запись предоставил International Rice Research Institute