Response Analysis Of Two Late Rice Varieties Population Characteristics And Yield Formation To Coupling Of Fertilization And Density

This experiment was conducted in 2018-2019 at the practice base of Hunan Agricultural University,Hedong Farm,Liuyang City,Hunan Province,under two different planting modes(winter crops are potato and rape,early rice varieties are Zhongjiazao 17 and Lu Liangyou 996),using late rice varieties Xiangwanxian 17 and Hyou 518 as materials,set up6 slow-release nitrogen fertilizers combined application mode: no nitrogen fertilizer as control(N1),conventional urea(N2),slow-release nitrogen fertilizer and conventional urea 5 : 5 combined application(N3),slow-release nitrogen fertilizer and conventional urea30% each for weight loss(N4),slow-release nitrogen fertilizer and urea 30% each for organic fertilizer(N5),slow-release nitrogen fertilizer and urea 30% each for weight loss Combined application of biochar(N6)and three machine insertion densities D1(11cm×25cm),D2(14cm×25cm),D3(17cm×25cm),with a view to clarifying fertilizer reduction and combined application on rice growth population characteristics and yield Impact,providing technical support for the efficient rice cultivation technology system in Hunan,the main results are as follows:1.Under N5 and N6 treatments,the dry matter weight of the two varieties increased significantly in the early growth period compared with the treatments.In the late growth period,the dry matter weight of the N5 treatment group increased significantly at the full-heading stage and the mature stage compared to the treatments.The N5 treatment of Xiangwanxianxian 17 increased the dry matter accumulation in the whole growth period under the rice and rice oil and rice and potato planting modes,and H You 518 performed the same under the rice and potato mode.2.The net photosynthetic rate,stomatal conductance,and intercellular carbon dioxide concentration of Xiangwanxian 17 at D1 and D2 densities at booting stage were higher than those of all treatments.The net photosynthetic rate at D1 and D3 densities at the full panicle stage significantly increased At the booting stage,N5 treatment H You 518 had the highest net photosynthetic rate at D1 density,and at the heading stage D2 density,the net photosynthetic rate and intercellular carbon dioxide concentration were significantly higher than those of each treatment.3.Under the rice-potato model,the plant height of Xiangwandian 17 was significantly reduced under the treatment of D1 density and N5.The single stem resistance was the highest in N5 treatment.The thrust resistance of single stem is the highest with N5,and the stem thickness is increased and the bending moment is reduced under D1 density.Under the rice-oil model,Xiangwanxian 17 under N5 treatment can significantly reduce the stalk type index,increase the stem thickness,and increase the single stem resistance.4 The overall yield is rice oil>rice potato,H You 518>Xiangwanxian 17,density D1>D2>D3,and N5 treatment has the most obvious effect on yield increase during fertilizer treatment.Under the two planting modes,N5 treatment can significantly increase the effective ear number,seed setting rate,thousand-grain weight and yield.Compared with N2 treatment,the two varieties increased yield by 30.81%,32.66%,36.78% and 28.61%respectively.