Guan'gai paishui xuebao (Jan 2022)
Change in Japonica Rice Growth Traits with Agronomic Cultivation and Water-saving Irrigation
Abstract
【Objective】 One constraint in agricultural production in many regions of China is the imbalance between the dwindling water resources and the increasing demand of different sectors for it. Implementing saving-water irrigation to partly thirst the crops without compromising their yields is one of many solutions. Taking japonica rice as an example, this paper is to investigate the response of its growth traits and yield to change in irrigation and cultivation. 【Method】 The experiment was conducted in lysimeters and compared three irrigations: deep wetting irrigation (SR), controlled irrigation (KZ) and shallow wet irrigation (QS). For each irrigation, there were two cultivations: direct seed drilling in water (SZB) and direct dry seed drilling (HZB), with traditional transplant cultivation used as the control. In each treatment, we measured the growth traits, water consumption, yield and yield components of the crop. 【Result】 When the seed drilling was the same, KZ was most effective in terms of tillering, water consumption and grain yield; its water productivity was comparable to that of SR - the optimal irrigation giving the highest yield. Compared to KZ, QS increased water consumption by 19.90%, reduced yield and water productivity by 4.22% and 20.11% respectively. SR was least effective in tillering, despite leading to higher plant height than KZ; it had the lowest water consumption and highest water productivity, but its yield was much lower than that of KZ and QS. When the irrigation method was the same, the direct seed drilling delayed crop growth in the initial stage compared to the control, but this can be compensated for in the middle-late tillering stage, especially SZB whose tiller numbers were approximately the same as that of the control. Under the same irrigation, the yield of direct seeding was lower than that of the control, especially HZB. Compared with the control, under different irrigation methods the yield of SZB was higher than that of SR and its water productivity was higher than that of QS. There was a little difference in water consumption between the two seed drilling methods when the irrigation method was the same. Comparative analysis showed that, on average, SZB was superior to HZB. 【Conclusion】 In terms of irrigation, controlled irrigation was most effective in saving water use of the japonica rice, followed by the shallow wet irrigation. In terms of cultivation, transplant had the highest yield regardless of the irrigation methods.
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