Effects Of Different Irrigation And Nitrogen Supply Methods On Distribution,absorption And Utilization Of Water And Nitrogen In The Soil And Crop In Linfen Basin

In order to improve the water use efficiency(WUE)and nitrogen use efficiency(NUE)of winter-wheat and summer-maize in Linfen basin,it was studied the effects of different irrigation and nitrogen supply methods among flood irrigation with broadcast fertilizer(FIBF),drop irrigation fertigation(DIF)and micro-sprinkler irrigation fertigation(MIF)on winter-wheat and summer-maize.The research focused on six parts content,including distribution and migration of water and nitrogen in the soil,leaf photosynthesis,accumulation and distribution of dry matter,absorption and distribution of N in Crop,yield,WUE and NUE.The main results were as follows:1.Each process in all levels of soil water content significantly increased after irrigation.Soil moisture content which under FIBF mainly concentrated at the 1-1.6 m soil depth,under DIF and MIF were mainly distributed at 0-1 m soil depth;Water infiltration rate and the reproductive period variations in soil were characterized by FIBF > MIF > DIF.Under the condition of the same total fertilizer,reservoir capacity of the crop showed a trend of decrease after the first increase during the filling stage.Due to the local farmers used to using flood irrigation for irrigation in over-wintering stage and jointing stage irrigation,the filling stage of wheat had been affected by drought stress,while flood irrigation water volume to a minimum in mature period.It was illustrated that too much water actually can not be use fully,and DIF and MIF can be divided into a small amount of water for many times,ensured the water storage capacity of winter-wheat and summer-maize in the late of grouting.DIF and MIF were more conducive to the formation of crop seeds.2.DIF and MIF is beneficial to maintain nitrate nitrogen content at 0-60 cm soil depth.The content of nitrate nitrogen at 0-60 cm soil depth were DIF > MIF > FIBF.The content of ammonium nitrogen and water content at 0-160 cm were positively correlated.DIF and MIF were more advantageous to the distribution of nitrate nitrogen and ammonium nitrogen at 0-60 cm soil depth in the early stage of the crop growth,and distribution at 60-160 cm soil depth in the late of crop growth.FIBF will accelerate soil nitrate nitrogen and ammonium nitrogen leaching.3.The photosynthesis of wheat was promoted under DIF and MIF.Under the condition of same amount of fertilizer with different irrigation ways,DIF and MIF made the value of SPAD,Pn,Gs,Fv/Fm,Fv/F0,Qp and ? PS?were larger than FIBF,and achieved the lowest value before irrigation fertilization in the filling stage,achieved peak value after irrigation fertilization in the filling stage.The value of ETR increased,the value of Ci,NPQ to a minimum.It showed that watering and fertiling in filling stage can improve the dry matter of flag leaf photosynthesis,and it was beneficial to wheat grouting material production.4.DIF and MIF increased crop plant height,leaf area index(LAI)and dry matter accumulation.Late crops increased irrigation frequency can keep green leaf area,which is conducive to the synthesis and accumulation of photosynthate.The fastest period of Wheat growth was jointing stage to tasseling stage,it grown on average 1.13cm~1.76 cm a day.The fastest-growing growth period of maize was from small bell mouth period to tasseling stage,it grown on average 5.36cm~8cm a day.LAI under DIF and MIF were still significantly greater than under FIBF when it was irrigated for the third time in the late of crop growth.Total dry matter of summer corn under DIF and MIF were significantly higher than BIBF 12.1% and 11.0% respectively on tasseling stage.The proportion of dry matter of winter wheat organs in mature period was: grain > stem+sheath > spike+husk > leaf,summer corn was: grain > stem+sheath > leaf > cob+husk.5.The best method for nitrogen accumulation of organs above ground of winter-wheat and summer-maize was DIF,better method was MIF,the worst method was FIBF.The distribution ratio of organs above ground on nitrogen of winter wheat in mature was grain > stem+sheath > leaf > spike+husk.When summer maize mature organs of nitrogen distribution proportion for grain > stem+sheath > leaf > cob+husk.DIF and MIF were beneficial to increasing the summer maize stem+sheath,cob+Husk of nitrogen transport rate and the contribution rate of grain.6.DIF and MIF could improve crop yield,WUE and NUE.Compared with FIBF,DIF and MIF increased the crop yield,reduced the water consumption,increased WUE and NUE.Compared with FIBF,the yield of winter-wheat under DIF and MIF increased by 3.35% and 2.79% respectively.the yield of the summer-maize increased by 23.22% and 23.22% respectively.WUE of winter-wheat increased by 77.57% and 77.57% respectively,WUE of summer-maize increased by 111.66% and 91.15%,respectively.NUE of Winter-wheat increased by 3.32% and 2.79% respectively,NUE of summer-maize increased by 23.23% and 20.95%,respectively.In a word,compared with FIBF,DIF and MIF with postponing water and nitrogen topdressing were more conducive to the coordinated water and nitrogen supply,promoted the growth of winter-wheat and summer-maize,improved the utilization rate of water and nitrogen.We suggest using DIF or MIF mode in linfen basin.