模拟稻渔共作深水栽培条件下增苗减氮对水稻产量及茎秆抗倒伏性能的影响OA

[Objective]This study aimed to clarify the impact of reducing nitrogen input while increasing seedling density on rice growth and yield formation under deep-water cultivation,with the goal of achieving dual harvests of both rice and fish.[Method]Four rice varieties,including both conventional and hybrid types,were selected to simulate the rice-fish co-culture environment.During the experiment,high water levels were maintained,and it was set as follows:CK,applying nitrogen fertilizer in a ratio of base fertilizer:tiller fertilizer:panicle grain fertilizer=5:3:2,with one basic seedling per hole;three treatments were used to increase seedlings and reduce nitrogen,with only basal fertilizer applied as nitrogen fertilizer.T1,T2,and T3 were 2,3,and 5 basic seedlings per hole,respectively;the study examined the yield and its components,SPAD values,and internode lengths.[Result]Under the seedling-increase and nitrogen-reduction model,as the basic seedlings per hole increased,the effective panicles per plant significantly rose,while the grains per panicle,seed-setting rate,and 1 000-grain weight declined to varying degrees.With 5 basic seedlings per hole and only basal fertilization(T3),the effective panicles per hole of Taiyou871 and Huaxiangmati increased by 168.4%and 169.9%compared to CK,respectively.However,Huaxiangmati showed a larger reduction in grains per panicle,reaching 24.7%.Due to the substantial increase in effective panicles per plant under the seedling-increase and nitrogen-reduction model,the yield of all varieties improved significantly.Under treatments T2 and T3,the single-plant yield of Taiyou871 increased by 59.7%and 91.7%,respectively,while that of Huaxiangmati rose by 35.9%and 75.9%.Additionally,under this model,the panicle length and secondary branch numbers significantly decreased,with Taiyou 871 showing a 10.0%reduction in panicle length and a 15.0%decrease in secondary branches.However,it revealed no significant changes in SPAD values of flag leaf under the seedling-increase and nitrogen-reduction model.Additionally,as the number of seedlings per hole increased,the internode length of for the third and fourth internode counted from top to bottom rice-plants would increase to varying degrees,which to some extent reduced the lodging resistance of the plant stems.[Conclusion]Proper seedling growth and nitrogen reduction under deep water cultivation have a certain effect on rice yield formation,which is worthy of further research.