减氮和增氧灌溉对水稻产量和氮素利用的影响

【目的】明确减氮和增氧灌溉对水稻生长、产量和氮肥利用的影响。【方法】以3个品种水稻中旱221(旱稻)、中浙优8号(水稻)和IR45765-3B(深水稻)为材料，并设常规施氮量(195.0 kg/hm²)、减施氮量(157.5kg/hm²)2种氮水平和常规淹水灌溉(ConventionalFloodIrrigation,WL)、微纳米气泡水增氧灌溉(Micro-nanoBubbleWater OxygenationIrrigation,MBWI)2个灌溉模式，对比分析了3个品种水稻的茎蘖动态、叶片叶绿素含量、叶面积、干物质量、产量和水稻的氮素吸收利用特征。【结果】研究结果表明，MBWI处理显著增加了水稻产量，中旱221、中浙优8号和IR45765-3B的2年平均产量MBWI处理分别比WL处理增加12.4%、7.5%和6.7%，这可能与水稻有效穗数、每穗粒数密切相关。微纳米气泡水增氧灌溉和增施氮肥用量显著增加水稻叶片叶绿素含量和叶面积，并增加水稻干物质积累量。氮肥和增氧灌溉均影响水稻各氮素利用率指标，与淹水灌溉相比，微纳米气泡水增氧灌溉均可以显著...

Effects of Nitrogen-reducing and Oxygen-increasing Irrigation on Rice Yield and Nitrogen Use Efficiency

【Objective】 To clarify the effects of nitrogen reduction and oxygen-increasing irrigation on growth, yield and nitrogen utilization of rice.【Method】 Three rice varieties Zhonghan 221 (upland rice), Zhongzheyou 8 (rice) and IR45765-3B (deep water rice) were used as materials, and two nitrogen levels of conventional nitrogen application level(195.0 kg/hm²), reduced nitrogen application level (157.5 kg/hm²) and two irrigation modes of conventional flooding irrigation (WL) and micro-nano bubble water oxygen enhancement irrigation (MBWI) were designed. The tiller dynamics, leaf chlorophyll content, leaf area, dry matter quality, yield and nitrogen absorption and utilization characteristics of the three rice varieties were compared and analyzed. 【Result】 The results showed that MBWI treatment significantly increased rice yield, and the 2-year average yield in MBWI treatment was 12.4%, 7.5% and 6.7% higher than that of WL treatment, respectively, which may be attributed to the number of effective panicles and grains per panicle. The amount of micro-nano bubble water oxygenated irrigation and nitrogen fertilizer significantly increased the chlorophyll contents and leaf area of rice leaves, and increased the dry matter accumulation of rice. Both nitrogen fertilizer and aerobic irrigation affected the nitrogen use efficiency of rice. Compared with flooded irrigation, micro / nano bubble water aerobic irrigation could significantly increase the nitrogen harvest index, nitrogen partial productivity and nitrogen grain production efficiency of the three rice varieties, reduced nitrogen transport efficiency and nitrogen transport contribution rate of rice. Nitrogen reduction treatment significantly increased nitrogen transport efficiency, nitrogen transport contribution rate, nitrogen grain production efficiency and nitrogen partial productivity, but decreased nitrogen harvest index.【Conclusion】 Aerobic irrigation can increase the chlorophyll contents and leaf area of rice leaves, thus increase the number of tillers and dry matter accumulation of rice, and then significantly increase rice yield and affect the characteristics of nitrogen utilization. Under the conditions of reduced nitrogen application in paddy field, oxygen-increasing irrigation can help build a high-yield population and maintain a higher yield.