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| DOI：10.13522/j.cnki.ggps.2017.0151 |
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| Relationship between Waterlogging and Cotton Yield |
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CHENG Lunguo, ZHU Jianqiang, WU Liren, YE Hao
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1. Experimental Station of Irrigation and Drainage, Sihu Engineering Administration of Jingzhou City, Jingzhou 434013, China; 2. College of Agriculture, Yangtze University, Jingzhou 434025, China; 3. Farmland Irrigation and Drainage Experiment Station of Tianmen, Tianmen 431719, China
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| Abstract: |
| 【Objective】 The objective of this paper is to present a quantitative relationship between waterlogging and cotton yield based on seven years’ experimental data.【Method】 From May to August in each year from 1999 to 2016, we measured waterlogging in a cotton field and classified the waterlogging into four categories: subsurface waterlogging, multiple subsurface waterlogging, one subsurface waterlogging followed by surface waterlogging, combination of multiple subsurface waterlogging and surface waterlogging. Subsurface waterlogging was represented by accumulated groundwater depth when it was 30 cm below the ground surface (SEW30), and surface waterlogging was represented by rainwater dynamic index (SFW) that was the accumulated surface water depth within a defined period. The combined effect of surface and subsurface waterlogging (SFEW30) was expressed by the sum of SEW30 and SFW. The impact of these waterlogging events on cotton yield was analyzed based on experimental data collected in the seven years.【Result】 Reduction in cotton yield was 8% for one-off subsurface waterlogging with groundwater table (Tg-30) was not shallower than 30 cm for 2~4 days, and 10%~20% for multiple subsurface waterlogging when the accumulated waterlogging time Tg-30 was between 10 days to 20 days. For subsurface waterlogging followed by surface waterlogging, the reduction in cotton yield was 25.8%~49.1% when the cotton was under waterlogging for 4~10 day during blossoming and/or boll-forming stages with Tg-30 being 7~13 days. The reduction in cotton yield was 35.0%~49.5% no matter what stage the cotton was, if the plants suffered multiple waterlogging within 5 days and the cumulative time of the waterlogging lasted more than five days. 【Conclusions】The waterlogging indexes SEW30, SFW, and SFEW30 proposed in this paper can be used to predict reduction in cotton yield. |
| Key words: waterlogging; cotton field; relative yield; quantitative analysis |
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