Effects Of Water And Fertilizer Coupling On Material Production And Yield Of Super Rice

In view of the shortage of water resources and the phenomenon of nitrogenous fertilizer production in rice production,in order to make rational use of water and nitrogen resources and promote the sustainable development of rice production,in 2018,the early rice variety two you 819,Lu Liangyou 996,late rice variety H you 518 and five feng you T025 were used as materials in Meihua village,Xi Du Town,Hengyang county.2 irrigation methods(G1 aerobic irrigation-G2 conventional irrigation)and 4 nitrogen levels(D1,D2,D3,D4),0,112.5,150,187.5kg/ha,and 0,135,180 and 225kg/ha of late rice were studied.The effects of water and fertilizer coupling on the material production and yield of double cropping super rice were studied.The main results are as follows:(1)nitrogen application promoted the biological yield of rice.Under the condition of high fertilizer,wet irrigation was beneficial to dry matter accumulation of panicle.The dry matter accumulation of all nitrogen treatments was significantly higher than that of no nitrogen control D1.With the increase of nitrogen application rate,the total dry matter weight and dry matter weight of all organs also increased.At the level of no fertilizer to medium fertilizer level(D1,D2,D3),The dry matter accumulation of Panicle in mature stage was greater than that in wet irrigation.However,under the high level of fertilizer(D4),wetting irrigation was greater than flooding irrigation,indicating that the higher the level of fertilization,the less suitable for flooding irrigation.(2)nitrogen application and submergence irrigation were beneficial to maintaining high SPAD value of leaves.Under wet irrigation(G1),the SPAD value of leaves at the early tillering stage was the lowest,from tillering stage to booting stage,and the growth rate of booting stage to full heading stage slowed down.The SPAD values of D1,D2 and D4 before and after full heading stage decreased under the condition of conventional irrigation(G2).The SPAD values of D3 and D4 in the whole growth stage showed a trend of increase,which were higher than those of D1 and d2..(3)nitrogenous fertilizer and humid irrigation promoted the nitrogen metabolism of rice.The nitrate reductase activity of rice increased with the increase of nitrogen application rate.Under the same nitrogen application rate,the nitrate reductase was treated with wet irrigation G1 during the whole growth period,which was higher than that of conventional irrigation g2..Under the same irrigation condition,there was a significant difference between the high nitrogen treatment D4 and the blank control D1.However,there were significant differences in D1 at tillering stage and booting stage compared with blank control.(4)wetting irrigation and increasing nitrogen fertilizer increased the leaf area index of rice.Under the same irrigation mode,the leaf area index(LAI)of rice increased with the increase of nitrogen fertilizer application.Under the same nitrogen level,the total trend of Lai was G1 wetting irrigation and G2 flooding irrigation.At tillering stage,G1 treatment was higher than that of significant G2 treatment.G1 was slightly higher than that of G2 treatment.There was little difference in water treatment at the same nitrogen level at the same heading stage,while leaf area index was slightly higher in g1d3 and g1d4 treatments.Under the experimental conditions,the total yield of rice increased with the increase of nitrogen application rate,while that of wet irrigation was higher than that of flooded irrigation.The yield of early rice using nitrogen fertilizer was higher than that of the control without nitrogen fertilizer,and that of late rice was significantly higher than that of4.3%-59.2%.However,the difference between D3 and D4 was not significant.Taking account of the fertilizer utilization rate,the economic benefits of fertilization and the environmental impact,the yield of rice was significantly higher than that of 7.2%-48.2%.The best combination of treatments in this experiment is G1D3,namely wet irrigation.The amount of nitrogen applied early and late rice is pure N 150.0kg/ha and 180.0kg/ha respectively.