控制灌溉增氧对超级稻生理生化特性及水分利用效率的影响

为了提升超级稻灌溉用水的利用效率,采用控制灌溉技术与增氧灌溉技术相结合的灌溉方式进行试验.以超级稻“陵两优268”为研究对象,设置4组处理:控制灌溉机械增氧(JX)、控制灌溉超微泡增氧(WP)、控制灌溉(CK)、淹水灌溉(YS),探究控制灌溉条件下增氧对超级稻返青期后的各生育期生理生化特性指标及产量的影响.试验表明,叶片叶绿素含量,在水稻分蘖期、拔节孕穗期、抽穗开花期差异并不明显,但乳熟期最大提升了38.2%.净光合速率、蒸腾速率、气孔导度均有显著提升,其中在抽穗开花期,早稻分别提升了44.9%,18.5%,25.0%;晚稻分别提升了14.3%,11.5%,22.2%.根系活力,在抽穗开花期,对比YS组最大提升了44.6%,对比CK组最大提升了11.5%.同时,对土壤氧化还原电位进行定期监测,得知控制灌溉条件下增氧处理后,其各时期基本均处于氧化态,而淹水灌溉下基本处于还原态.在全生育期耗水量上,控制灌溉条件下3组处理的节水效率显著提高,控制灌溉增氧条件下全生育期最大有效节水达18.5%.

Effects of controlled irrigation and oxygenation on physiological andbiochemical characteristics and water use efficiency of super rice

A combination method of controlled irrigation and aerobic irrigation was adopted in field experiments of super rice to improve its water use efficiency.The super rice of brand Lingliangyou 268 served as study object,and four experimental treatments were designed,namely controlled irrigation and mechanical aeration(JX),controlled irrigation and ultra-microbubble aeration(WP),controlled irrigation(CK),flooding irrigation(YS)to explore effects of aeration on physiological and biochemical characteristics and yield of the rice during its growth periods after turning green under controlled irrigation conditions.The results show that the content of chlorophyll in leaves is not significantly different in the early growth stages(tillering stage,jointing booting stage,heading and flowering stage),but it is increased by 38.2%in maximum in the late growth stage(milk stage).The net photosynthetic rate,transpiration rate and stomata conductance are significantly improved,specially,in the early stages increased by 44.9%,18.5%,and 25.0%,respectively,but 14.3%,11.5%,and 22.2%in the late stage.Compared with the YS group,the root vigor rises by 44.6%in maximum,but 11.5%against the CK group in heading and flowering stages.At the same time,the soil redox potential is re-gularly monitored.The soil is basically in oxidation state during various growth periods after aerobic treatment under controlled irrigation conditions.Under flooding irrigation,however,the soil is essentially in reduced state during the whole growth period.The water use efficiency is improved significantly in three groups under controlled irrigation conditions,especially,the maximum water saving is up to 18.5%during the entire growth period under controlled irrigation condition with oxygenation.