| Selection of its varieties is one of the effective ways to improve the level of the corn yield.Subsoiling is beneficial to improve the soil structure,promote root system,increase the absorption and utilization of water and nutrients,delay the senescence ofmaize plants and increase the yield.Therefore,in order to explore the change of Maize Varieties in China adaptation to planting density increased,and then explore the mechanism of yield increase of maize density,this study use different in maize varietieswere tested in different planting density and subsoiling,its difference in different varieties of analysis,reveal the hybrid corn density tolerance the evolution characteristics and differences of physiological mechanism of different age.At the same time,the deep loosening densification measures of different maize varieties resistant to differences in the response of subsoiling,further elucidate the physiological mechanism of high density of high yield maize subsoiling densification response.The results are as follows:(1)Maize varieties in different years,with the increase of planting density in advance,and after subsoiling ear leaf angle becomes small,leaf orientation value increased,leaf area decreased,thereby thickening group after LAI.In the different maize varieties to subsoiling densification reactions are different,and in recent years varieties of high density tolerance is better.(2)With different ages,the leaf SPAD value and leaf photosynthetic rate of different layers of the maize varieties in different ages showed the position of the ear leaf,upper leaf and lower leaf.After deep loosening and densification,the maize varieties in recent years effectively delayed the senescence of the lower position leaves of the lower leaves,and increased the photosynthetic rate.(3)Over the years to promote Maize Varieties in different years,the single peak curve trend of maize root dry weight,root length,root surface area and root average diameter was increased and then decreased,with the advance in deep soil(20-50cm)root accounted for significantly increased compared to the total cases.Reduce the corn root water and nutrient absorption and make full use of.(4)Modern maize varieties in the deep pine increased maize root configuration isbetter than before after the close,the root of Maize Varieties in recent years and more fine,due to the resistance caused by the density increase of root dry weight,root length,root surface area decreased enhancement was lower than in other maize varieties,while the dry weight of root in deep soil root length,root surface area,the proportion is higher than the other varieties in maize.(5)Maize varieties in different years,as in advance,maize yield was increased,and the performance of subsoiling is greater than the shallow rotary treatment,high density treatment was higher than that of low density,and the deep pine density increasing,maize varieties in recent years due to its better group to obtain advantage high yield.Therefore,it is easier to realize the high yield and high efficiency cultivation of the modern varieties by adopting the method of deep loosening and densification. |
