Effects Of Micro-spray Supplementary Irrigation And Fertilizer On Yield,water And Nitrogen Utilization Efficiency Of Different Winter Wheat Varieties

In order to explore the effect of micro spray supplementary irrigation water and fertilizer integration on Winter Wheat Yield and water and nitrogen utilization efficiency,different water and fertilizer management models were tested in winter wheat growing season from2019 to 2021.Shannong 29 and Jimai 229 were used as test materials.Two irrigation methods,border irrigation（W1）and micro spray supplementary irrigation（W2）,were set,with three nitrogen application levels of 240 kg hm^-2（N1）,192 kg hm^-2（N2）and 0 kg hm^-2（N0）.There were two top dressing methods at jointing stage:uniform nitrogen supply with water（T1）and local nitrogen supply with furrow and strip（T2）.The effects of different water and nitrogen supply modes on root morphology,physiological activity,yield and water and nitrogen utilization efficiency of winter wheat were studied.The main results are as follows:1 Effects of water and nitrogen supply on water consumption characteristics and water use efficiency of winter wheatUnder the same nitrogen fertilizer level,the total water consumption of W1T1 treatment had no significant effect on that of W1T2 treatment;Compared with W2T2 treatment,W2T1treatment significantly increased soil water storage consumption,and then increased total water consumption and water use efficiency.Under the same irrigation mode,N2T1 treatment reduced the consumption of soil water storage and increased the proportion of water consumption between irrigation and precipitation;Under the same nitrogen fertilizer level,compared with w1t1 treatment,W2T1 treatment significantly reduced the amount of irrigation,increased the consumption of soil water storage,and significantly improved the efficiency of irrigation water use and water use efficiency.2 Effects of water and nitrogen supply on soil nitrate distribution in wheat fieldThe content of nitrate nitrogen in 0-80 cm soil layer at flowering stage and 0-120 cm soil layer at maturity stage of fertilization line in T2 treatment was significantly higher than that in T1 treatment.Under the same nitrogen fertilizer level,the content of nitrate nitrogen in 0-30cm soil layer of W1T1 treatment was significantly higher than that in non fertilization soil layer of W1T2 treatment;The content of nitrate nitrogen in 0-60 cm soil layer of W2T1treatment at flowering stage and maturity stage was significantly higher than that in the corresponding soil layer of non fertilization line of W2T2 treatment.Under the same irrigation mode,the content of soil nitrate nitrogen in N1T1 treatment was higher than that in N2T1 treatment;Under the same nitrogen fertilizer level,the content of soil nitrate nitrogen in100 cm-200 cm soil layer of W2T1 treatment was significantly lower than that of W2T2treatment.3 Effects of water and nitrogen supply on root morphology and activity of winter wheatIn W1 mode,the root length density,root surface area density and root weight density in0-20 cm soil layer at flowering and maturity were significantly higher than those in T2 treated fertilized and non fertilized rows.There was no significant difference in root activity in 0-20cm soil layer after flowering and T2 treatment;The root length density,root surface area density and root weight density of fertilization row in 0-40 cm soil layer of T2 treatment were significantly higher than those of non fertilization row,and there was no significant difference in root activity between the two rows.In W2 mode,the root length density and root surface area density in 0-40 cm soil layer at flowering and maturity stage were significantly higher than those in fertilized and non fertilized rows of T2 treatment,and the root activity in 0-20cm soil layer after flowering was significantly higher than that in T2 treatment;The root length density,root surface area density,root weight density and root activity in 0-100 cm soil layer of T2 treatment were significantly higher than those in non fertilization row.It shows that the integration of water and fertilizer for micro-spray supplementary irrigation can optimize the root distribution and improve the root absorption area and intensity.4 Effects of water and nitrogen supply on dry matter accumulation,transport and distribution of winter wheatUnder the same nitrogen fertilizer level,top dressing at jointing stage had no significant effect on dry matter accumulation and distribution under border irrigation;Compared with W2T2 treatment,W1T1 treatment can improve the net photosynthetic rate after anthesis,promote the synthesis of assimilates after anthesis,promote the transport of assimilates before anthesis to grains,and improve grain yield and distribution ratio.Under the same irrigation mode,compared with N1T1,N2T1 decreased the amount of assimilate after anthesis and increased the amount of assimilate before anthesis to grain;Under the same nitrogen fertilizer level,W2T1 maintained higher post anthesis photosynthetic rate and dry matter assimilation than W1T1,and promoted the transport of pre anthesis assimilates to grains.5 Effects of water and nitrogen supply on nitrogen accumulation,transport and utilization in winter wheatUnder the same nitrogen fertilizer level,there was no significant difference in grain nitrogen accumulation between W1T1 treatment and W1T2 treatment;Compared with W2T2treatment,W2T1 treatment significantly increased the transport of nitrogen to grain before anthesis and the amount of nitrogen assimilation after anthesis,and finally improved the grain nitrogen accumulation,nitrogen absorption efficiency and nitrogen partial productivity.Jimai229 also improved the internal nitrogen utilization efficiency.Under the same irrigation mode,compared with N1T1,N2T1 grain nitrogen accumulation decreased,but nitrogen harvest index,nitrogen absorption efficiency and nitrogen partial productivity increased significantly;Under the same nitrogen fertilizer level,compared with W1T1,W2T1 grain nitrogen accumulation,nitrogen harvest index,nitrogen absorption efficiency and nitrogen partial productivity increased.6 Effects of water and nitrogen supply on yield and yield composition of winter wheatUnder the same nitrogen fertilizer level,top dressing at jointing stage had no significant effect on yield under border irrigation;Compared with W2T1 treatment,the number of grains per ear and 1000 grain weight of Shannong 29 variety W2T2 treatment decreased,and the number of grains per ear of Jimai 229 variety decreased,resulting in the decline of yield.Under the same irrigation mode,with the increase of nitrogen application rate,the number of panicles and grains per panicle increased,and the 1000 grain weight decreased significantly.The yield of Shannong 29 was N1>N2,and Jimai 229 was N2>N1,but they did not reach a significant level;Under the same nitrogen fertilizer level,compared with W1T1 treatment,W2T1 panicle number and grain number per panicle decreased,1000 grain weight increased,and the yield difference between W2T1 and W1T1 was not significant.To sum up,Shannong 29 and Jimai 229 both obtained higher grain yield under the condition of micro spraying,supplementary irrigation,water and fertilizer integration.At the same time,under this condition,20%nitrogen reduction still maintained a high level on grain yield,and improved the utilization efficiency of water and nitrogen.