| In order to compare the effects of dressing different forms of nitrogen fertilizer under different base fertilizer on the nitrogen concentration,population dynamics and yield of wheat plants,and to explore the feasibility of nitrogen regulation on group construction,we conducted a two-year field location test from 2015 to 2017 ontwo different genotype varieties :Yumai49-198 and Zhoumai 16,applying 3 basal nitrogen levels(0,90 and 180 kg/ha)and 4 topdressing nitrogen forms(nitrate,ammonium,amide,ammonium and nitrate nitrogen fertilizer),and we analyzed the effects and correlativity of dressing different nitrogen amount and nitrogen forms and their interaction effects on the nitrogen concentration,population dynamics and yield of wheat in different growth stages.The main results were as follows:1.Effect of different nitrogen fertilizer forms on nitrogen uptake and use efficiency of wheatThe nitrogen content of wheat plants increased significantly with increasing of basal nitrogen amount.The effect of nitrogen fertilizer on the nitrogen content of wheat varied with growth period and nitrogen application level.While the basal fertilizer level is 0 and 90 kg·hm-2,the nitrogen concentration of amide nitrogen was significantly higher than that of ammonium nitrogen,and the nitrogen concentration was the highest in nitrate fertilizer.With the increase of nitrogen fertilizer,the SPAD of wheat significantly increased among 0-30 d after fattening,whereas there was no significant difference between the nitrogen levels in the latter stage.In the different forms of nitrogenous fertilizer,the total nitrogen treatment was higher,while under the lower and middle nitrogen levels,for both cultivars ammonium fertilizer applying had a relative low SPAD value in the middle stage after the recovery.With the increase of the amount of nitrogenous fertilizer,the amount of nitrogen accumulation in the whole plant and each organ increased significantly.Under low and medium nitrogen levels,the accumulation of nitrogen in ammonium nitrogen treatment was significantly lower than that in other three treatments,and the treatment of ammonium nitrate was significantly higher than that of amide nitrogen.Before flowering nitrogen transfer capacity and contribution rate to grain increased with the increase of nitrogen application,transfer ratio reduced after an initial rising,nitrogen forms had an significant effect on nitrogen turn traffic,transshipment ratio before flowering,whilst no significant impact on contribution.The nitrogen absorption and utilization efficiency of wheat decreased with the increase of nitrogen supply.Under the low nitrogen and nitrogen levels,the nitrogen absorption and utilization efficiency of wheat were all the lowest in ammonium nitrogen treatment,and the difference between the morphological treatment of nitrogen fertilizer was not distinct at the high nitrogen level.With the increase of the amount of nitrogen,the nitrogen content of 100 kilograms of wheat grain was increasing,and the two varieties were treated with high nitrogen ammonium nitrate treatment,which was significantly higher than that of low nitrogen and middle nitrogen.2.Effect of different nitrogen fertilizer forms on population dynamics of wheatThe population of two varieties significantly increased with the increase of basal nitrogen.Among different forms of nitrogen treatments,ammonium nitrogen treatment caused higher nitrogen in groups under low nitrogen condition,,while with the lowest,Under the condition of middle and high nitrogen,ammonium nitrate was treated with high nitrogen,and ammonium nitrogen was the lowest.With the nitrogen supply increase of the base fertilizer,the peak value of tiller and the number of panicles increased significantly in single wheat plant in 2016-2017.There was a significant positive correlation between nitrogen concentration and population for each cultivar,however,at the same nitrogen level,there was no obvious correlation between the nitrogen concentration and the group.3.The effect of nitrogen forms on the accumulation and transport of wheat dry matterThe nitrogen and nitrogen forms significantly affected the accumulation and transport of wheat dry matter.The accumulation of dry matter of two cultivars,stem sheath and leaf was significantly increased with the increase of nitrogen supply.Under the same nitrogen(n)level,amide nitrogen treatment caused higher dry matter accumulation amount,nitrogen levels in two varieties respectively by amide nitrogen and ammonium nitrate is higher,the high level of nitrogen in ammonium nitrate under processing is higher.dry matter transport before flowering also increased with the increase of basal nitrogen amount,the contribution of filling wheat grain through dry matter transport from stem sheath is better than leaf blade,and treatment for nitrogen levels,different forms of nitrogen fertilizer vary among different varieties.Significant correlation exists between nitrogen fertilizer applying level,nitrogen fertilizer forms and their contribution rate to wheat leaf.4.Effects of nitrogen forms on wheat yield and yield componentsThe yield of wheat was different between annual season.With the increase of the base nitrogen fertilizer supply in 2015-2016,the yield of Zhoumai 16 was increased first and then decreased,with the highest at the condition when middle nitrogen level and nitrogen and ammonium nitrate was applied.The yield of Yumai 49-198 increased with ammonium nitrate treatment.In 2016-2017,when the amount of nitrogen applied was 180 kg/ha,the increase in the yield of the base fertilizer was not obvious,and the increase was significantly increased in Yumai49-198.The number of panicles of two varieties,thousand grain weight and nitrogen fertilizer were all decreased with the increase of nitrogen fertilizer.The morphology of nitrogenous fertilizer had a significant effect on it,but it was different in different nitrogen levels.The nitrogenous fertilizer was the highest in the low nitrogen level.5.Effects of nitrogen forms on soil inorganic nitrogen accumulationWith the increase of basal nitrogen supply,soil inorganic nitrogen content increased significantly in 0 to 30 cm soil layer,nitrogen under low nitrogen level to inorganic nitrogen content is higher,with ammonium nitrate nitrogen,high nitrogen levels in treatment is higher,and30 to 60 cm,60-90 cm soil layer soil fertilizer after early with nitrate nitrogen treatment,highest late volatile.The soil inorganic nitrogen content in soil layer 20 d was significantly correlated with plant nitrogen concentration.Based on the results of this experiment,amide nitrogen was recommended to apply under low soil nitrogen conditions,whileamide nitrogen or ammonium nitrate was recommended under medium soil nitrogen condition.The four types of nitrogen were available under the higher soil conditions.in this test,it is recommended that the base fertilize nitrogen fertilizer of Zhoumai 16 should be applied 90 kg/ha,and the amount of nitrogen fertilizer should be 90 kg/ha,which can be used for the fertilizer application of amide nitrogen or ammonium nitrate.The amount of nitrogen fertilizer applied to the base fertilizer was 180 kg/ha,and the amount of nitrogen fertilizer was 90kg/ha,and ammonium nitrate was better. |
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