Study On The Effect Of Sowing Depth On Grain Yield And Growth Development Of High-yield Maize In Xinjiang

In order to explore the effects of different sowing depths on the yield and growth development of high-yield maize in Xinjiang,different sowing depths were set up at Xinjiang Qitai Experimental Station from 2017 to 2018.KX3564 were used as experimental materials to study the effects of different sowing depths on dry matter accumulation,population structure,uniformity and yield of high-yield spring maize in northern Xinjiang,with two planting densities of 105,000 plants/hm~2(P1)and 135,000 plants/hm~2(P2),three sowing depth treatments of 3 cm(S3),5 cm(S5)and 7 cm(S7)and three mixed sowing depth treatments(corresponding uniformity were 2.78(F1),3.52(F2)and 3.93(F3),respectively),so as to provide theoretical basis for high and stable yield of maize in this region.The results were as follows:1 The Effect of Sowing Depth on Yield and Composition of Spring MaizeAccording to two-year experiments,the suitable sowing depth can significantly increase the yield of maize.Under the same density level,the yield decreases with the increase of sowing depth,while increases with the increase of uniformity of deep mixed sowing.That harvest ears decrease and Grain number per ear is the main reason for the yield decrease caused by the increase of sowing depth.Compared with other treatments,the yield of S3 treatment increases by 6.2%-23.3%on average.The number of harvest ears increases by 4.1%-16.2%on average.Grain number per ear increased by 11.7%-21.2%.2 The Effect of Sowing Depth on Biological Characteristics of Spring MaizeSowing depth affects growth period.With the increase of sowing depth,seedling emergence time and growth period.Seedling emergence of S7 is 2 days later than that of S3 while 1 day later than that of S5,and the growth period of S7 is prolonged 6 days and 2 days respectively than S3 and S5.Sowing depth significantly affected the ear height.The ear height among treatments is significantly different.Along with the increase of sowing depth,the ear height of S7,compared with S3 and S5,increases by 9.7 cm and 6.8cm,respectively;Sowing depth significantly affects dry matter accumulation.With the increase of sowing depth,dry matter decreases significantly,S3 has the highest amount of substance transfer after blossoming,with the increase by 22.2%-36.8%compared with other treatments,while S7 has the lowest amount;Sowing depth significantly affects LAI.LAI decreases with the increase of sowing depth,while S3 is the highest,increasing by 9.0%-21.9%compared with other treatments while S7 is the lowest.3 The Effect of Sowing Depth on Canopy StructureSowing depth affects canopy structure.With the increase of sowing depth,the light transmittance increases while the extinction coefficient decreases.The light transmittance of ear layer between treatments is greater than that of bottom layer.F3 bottom layer and ear layer have the lowest light transmittance,the largest leaf area index and the largest extinction coefficient,and the difference is significant.The transmittance of S7 layer is 62.7%and 58.4%higher than that of S3 and S5,respectively.The light transmittance of S7 ear layer is 78.2%and 61.7%higher than that of S3 and S5,respectively.4 Changes of Population Uniformity and Its Effect on the YieldSowing depth affects the uniformity of agronomic indexes.There is a significant positive correlation between the uniformity of agronomic indexes in different periods.Grain number per ear,1000-grain weight and grain uniformity per ear and yield have significant positive correlation with yield.The yield increases by 361.11,364.29 and 206.3 kg/hm~2 respectively for every 1 increase in Grain number per ear,1000-grain weight and grain uniformity per ear.Every time the Grain number per ear increases by 1,grain uniformity per ear increases by 0.95.The grain uniformity per ear increases by 1%,the uniformity of 1000-grain weight increases by 0.94.