Effects Of Difference Nitrogen Managements On Dry Matter Accumulation, Nitrogen Uptake And Distribution Of Spring Maize

In recent years, the yield of spring maize slowly increases in our province, environmentalpollution and other issues happened, because of excessive fertilization and nitrogen fertilizersingle species. According to the investigation and analysis of farmer practice and issues infertilizer application, in this study, the spring maize as the object, a field trial of five kinds ofnitrogen management in the same level of NPK was designed. The dry matter and nitrogen uptakeand distribution, leaf SPAD value and yield of spring maize were systematically researched. Themain results are as follows:1. Each treatment of spring maize leaf, stem and sheath dry matter accumulation trendsshows: increased at first, but gradually decreased later during whole growth period, achievemaximum at the tasseling stage. The order of dry matter accumulation of the three vegetativeorgans is leaf> stem> sheath at the tasseling stage; the order is stem> leaf> sheath at the maturitystage.The total dry matter of spring maize gradually increase, the vegetative organs proportion hasdecreased, but the reproductive organs proportion increases; the proportion of T1and T4treatmentvegetative organs is lower at the maturity stage. The order of the amount of dry matter transfer,transfer rate and the contribution rate is leaf> stem> sheath; the stem and sheath dry matter transfercapacity and transfer rate of T1, T2, T3and T4treatment are higher than that of CK treatment in5%significant levels; There was a very significant linear correlation between ear dry matter andyield at the maturity stage;2. The nitrogen content of leaves, stems and sheath decreased during whole growth period,nitrogen content achieve maximum at the jointing stage, the order of the nitrogen content of threevegetative organs is leaf> stem> sheath; From tasselling to maturity, nitrogen content of bract, coband grain also show a downward trend. During whole growth period, the leaf,stem and sheathnitrogen accumulation of each treatment increased at first, but gradually decreased later, achievemaximum at the tasseling stage; The order of nitrogen content of vegetative organs is leaf> stem>sheath. The bract and cob nitrogen accumulation of each treatment increased at first, graduallydecreased later, achieve maximum at the filling stage, grain nitrogen accumulation has been anincreasing trend. The order of grain nitrogen content is T4> T1> T2> T3> CK at the maturity stage. The size of the performance of the different treatments of nitrogen transfer: leaf> stem> sheath;There was a significant quadratic curve correlation between total nitrogen accumulation and yieldat the jointing stage; There was a very significant linear correlation between total nitrogenaccumulation and yield at the maturity stage;3. There was a positive correlation between the leaf and SPAD value at different growth stage.The SPAD value of leaves, stems and sheath decreased during whole growth period, SPAD valueachieve maximum at the jointing stage. The SPAD value of T3, T4treatment has been in a highlevel; The correlation coefficient between SPAD value and nitrogen content at the belling stage ishigher than that the jointing stage, the topdressing is very suitable at the belling stage. There was asignificant quadratic curve correlation between SPAD value and yield at the belling stage4. The yields of T1, T2, T3, T4treatment are higher than that of CK treatment, the yieldincreased to8.02%-21.23%; the order of yield under different nitrogen management is T4> T1>T3> T2> CK; The main influencing factors of spring maize yield is100-grain weight in this trial.