| In order todetermine the suitable nitrogen application rate and planting density for the lodging resistance of winter wheat in drip irrigation in northern Xinjiang,under the field experiment conditions,in the winter wheat growing season of 2015-2016,four nitrogen application levels were set using a single-factor randomized block design.For single-factor randomized block designs of 300kg/hm2（N1）,360 kg/hm2（N2）,420 kg/hm2（N3）,and 480 kg/hm2（N4）in the 2016-2017 winter wheat growing season,setting settings There were four density treatments:M1（525×104/hm2）,M2（600×104/hm2）,M3（675×104/hm2）,M4（750×104/hm2）.The effects of different nitrogen rates and planting densities on plant height,center-of-gravity height,internode length,base internode diameter,stem fresh weight,and stalk base internode resistance,basal stem section of drip-irrigation winter wheat were studied.The physicochemical characteristics such as inter-filling degree,lignin content,field lodging rate and the influence on yield factors.The relationship between the morphological characteristics,physicochemical characteristics and lodging resistance of wheat stalks was studied by correlation analysis.The main findings are as follows:1.With the increase of nitrogen application rate,the plant height,the height of center of gravity,the internode length,the height of the center of gravity,the proportion of plant height and the fresh weight per stem of drip-irrigated winter wheat showed an increasing trend,and the internode length of the internode was decreased.In the small trend,the mechanical strength and lodging resistance index of the stem base of winter wheat in the blooming stage,milking stage and dough stages were changed as N1>N2>N3>N4 with increasing nitrogen application rate.The mechanical strength and lodging resistance index of the stalk base showed flowering stage>milk ripening stage>wax ripening stage at different growth stages,and the higher the risk of lodging of late winter wheat.Different nitrogen application rates had a certain regulatory effect on the internode lignin content and stalk plumpness in base of drip-irrigation winter wheat.With the increase of nitrogen application rate,the internode lignin content of stem base gradually decreased,The internode filling degree of the basal section increased first and then decreased from the blooming stage to the wax dough stage.The N2 treatment was the highest among all growth stages,and reached a significant difference level with other treatments.With the increase of nitrogen application rate,the lodging rate of drip-irrigation wheat increased gradually,and the maximum lodging rate was as high as 84.62%.The difference between treatments was extremely significant（P<0.01）,and the yield was highest with N2 treatment,which was 6315.76 kg/hm2,Compared with N1,N3 and N4,the yields increased by 4.72%,6.69%and 13.59%,respectively,which were significantly different from the latter two.2.The plant height of winter wheat increased gradually with the increase of the density.In the blooming stage,the plant height of M1 treatment was decreased by 3.04%,6.23%and 7.20%compared with the treatments of M2,M3 and M4,respectively.The center of gravity of winter wheat was at blooming stage,milking stage and wax dough.During the blooming stage and the wax dough stage,the heights of the barycenters of the M3 and M4treatments reached significant differences（P<0.05）,and the bases of winter wheat were all increased with the increase of the density.The length of the internodes showed a trend of increasing first and then decreasing with the increase of the density,and reached the longest in the M2treatment.The lignin content and plumpness of the basal internodes decreased with the increase of the density.With the increase of the density,the lodging resistance index of the stems showed a decreasing trend.The M1treatment and M3 and M4 treatments all reached significant difference.Level（P<0.05）,M2 treatment and M4treatment reached a significant difference level（P<0.05）.The yield of each treatment was M2>M3>M1>M4.There was no significant difference between M1,M2,and M3 treatments.Both M4treatments had significant differences（P<0.05）.M2 treatment yields were higher than those of M3,M1,and M4 treatments.Increased by 1.82%,3.45%,and 10.77%.Aboveground biomass weight was highest at17937.5 kg/hm2 with M3 treatment.The field lodging rate of each treatment ranged from M4>M3>M2>M1.The highest M4 treatment field lodging rate reached 61.1%,increasing.Although the large density can increase the number of wheat spikelets for drip irrigation,it will also lead to a decrease in the number of grains per spike and 1000-grain weight,and it will cause serious lodging and a decrease in the harvest index,which will seriously affect the yield.In summary,under the experimental conditions,when the nitrogen application rate was 360 kg/hm2 and the planting density was 600×104/hm2,the grain yield of winter wheat under drip irrigation was the highest,the stem height was suitable,the gravity center height was relatively low,and the lodging resistance index was relatively low.Relatively high.Explaining the appropriate amount of nitrogen application can not only reduce the lodging risk of winter wheat in drip irrigation,but also coordinate the relationship between winter wheat yield components and increase the yield. |
