东北三省水稻干湿交替灌溉模式适宜性分区

为了研究不同灌溉模式下水稻耗水特征及水分利用效率,探讨节水灌溉模式在东北水稻种植区的适宜性,该文基于东北三省水稻种植区1981-2016年县域气象资料、水稻作物资料以及土壤资料,利用调参验证后的ORYZA(v3)水稻模型,模拟了过去36a淹水灌溉(flood irrigation,FL)和干湿交替灌溉(alternative wetting and drying irrigation,AWD)2种灌溉处理下水稻的产量、耗水量以及水分利用效率,并结合干湿交替灌溉模式产量的高产性和水分利用效率的高效性,综合分析干湿交替灌溉模式在研究区域适宜性。研究结果表明:1)1981-2016年2种灌溉模式下,研究区域水稻平均产量显著增加,呈由西南向东北减少空间变化特征;过去36a水稻耗水量整体呈显著下降趋势,空间上整体呈西高东低;水分利用效率整体呈显著提高趋势,淹水灌溉模式下分布南低北高,干湿交替灌溉模式下整体东高西低。2)与淹水灌溉相比,干湿交替灌溉模式下研究区域内水稻产量减少1%~19%,平均减少11%,但水稻耗水量可降低3%~26%,平均为15%,研究区域水分利用效率提高8%。3)干湿交替灌溉模式最适宜区集中分布在辽宁省辽河平原南部、吉林省扶余-蛟河一线及延吉地区、黑龙江省松嫩平原东南部,适宜区集中在辽宁省辽河平原南部凌海、海城等地区、吉林省中部的永吉-磐石-柳河口一线以及黑龙江省中东部的方正、富锦等地区,次适宜区位于辽宁省东部灯塔、开原等地区,吉林省镇赉、双辽地区及黑龙江省中东部铁力、饶河地区,较适宜区分布在辽宁省东北部铁岭、清原等地区,吉林省长白、洮南及黑龙江省西部富裕-林甸-安达一带。研究区域干湿交替灌溉模式对节约水资源及保证水稻高产高效具有重要意义。

Rice suitability zoning of alternative wetting and drying irrigation mode in three provinces of Northeast China

Abstract: Northeast China (NEC) is an important japonica rice production region, wherein rice production accounts for more than 50% of the national total japonica rice production. On the other hand, NEC region is one of the areas in China most susceptible to climate change, and the average temperature in NEC increased by 0.38°C per decade during the past five decades, while the precipitation decreased. The rice is produced under flood irrigation conditions (FL) in NEC which is facing a severe problem of scarcity in water resources. There is an urgent need for reducing water consumption for rice production by developing water-saving irrigation technologies. Therefore, to study the water consumption characteristics and rice consumption water use efficiency (WUEC) of rice under water-saving irrigation and FL patterns, and discuss the suitability of water-saving irrigation pattern, will provide a scientific basis for regional water-saving irrigation and play a vital role in rice production safety in Northeast China. Here, our goal is to examine the rice AWD (alternate wet and dry) suitability patterns based on a comprehensive assessment of rice yield and WUEC throughout NEC over the 36-year period from 1981 to 2016. In this paper, the agro-meteorological experiment station data which included weather, soil, phenology and management data were used to calibrate and validate the model based on nine cultivars selected for each region by using DRATES calibration program and trial-and-error method. The cultivar selected in the ORYZA simulation was the cultivar with the greatest number of years of cultivation during 1981 to 2007 within each province, and simulation with the longest-planted cultivar was more realistic and provided information for this study. The modeling was set up with the selected cultivar using the daily weather data from 1981 to 2016 for the 134 counties, rice crop data and soil data under FL and AWD management to simulate rice yield and water consumption. Based on model outputs, the WUEC was calculated for each weather station during the past 36 years and assessed at three province regional scales across NEC (Liaoning, Jilin and Heilongjiang Province). Then, combined with the yield and WUEC, the distribution patterns of rice AWD suitability were studied. The results indicated that, the rice yield decreased from southwest to northeast and showed a significant increasing trend during the period 1981 to 2016 under two irrigation patterns. The rice water consumption decreased significantly in the past 36 years and showed a decreasing trend from west to east. WUEC had increased significantly, with a decreasing distribution form north to south under FL and from east to west under AWD. Compared with FL, the rice yield under AWD decreased by 11% and varied considerably among locations (1% - 19%). However, the water consumption of rice decreased by 3% - 26%, with an average of 15%, and the averaged WUEC increased by 8%. The very suitable zone for AWD concentrated in southern Liaohe Plain of Liaoning Province, Fuyu-Jiaohe and Yanji region of Jilin Province, Southeastern Songnen Plain of Heilongjiang Province; suitable zone was in Linghai and Haicheng region in southern Liaohe plain of Liaoning Province, Yongji-Panshi-Liuhekou of central Jilin Province, Fangzheng and Fujin of central and eastern Heilongjiang Province; moderately suitable zone located in Dengta and Kaiyuan of the eastern Liaoning Province, Zhenlai and Shuangliao of Jilin province and Tieli and Raohe region of central and eastern Heilongjiang province; marginally suitable zone concentrated in Tieling and Qingyuan region of northeastern Liaoning Province, Changbai and Taonan of Jilin Province, and Fuyu-Lindian-Anda region of western Heilongjiang Province. It is of great significance to study AWD for saving water resources and ensuring high yield and high efficiency for rice in the research region.