Effects Of Different Planting Patterns On Photosynthetic Indexes And Yield Of Maize Population

Maize is an important food crop in China.In recent years,the growing area and yield of maize is increasing,which is of great significance to ensure food security in China.At the same time,as a C4 crop with high light efficiency,it has strong photosynthetic capacity and great potential to increase production.However,maize yield is greatly affected by cultivation technology,water and fertilizer conditions and environmental conditions.Therefore,the establishment of maize planting patterns adapted to different regions can improve the canopy structure,photosynthetic environment,root distribution and so on,which is conducive to high yield.The Songnen Plain is the main production area of spring maize in China.In recent years,the increase of maize yield mainly depends on the increase of density.However,there is no systematic study on the influence of planting patterns on the photosynthetic performance and yield of maize.The experiment was carried out under the climate and soil conditions in the middle of the Songnen Plain.Tiannong nine was used as the experimental material.Four planting patterns were set up,including DLSH planting pattern,SBK planting pattern,EBK planting patterns and JYL planting pattern.To study the effects of different planting patterns on the light distribution,photosynthetic performance and yield in the canopy of maize population,and to explore the suitable planting patterns in the Songnen Plain,so as to provide a theoretical basis for studying the photosynthetic performance of maize population and realizing yield increase.The main results are as follows:(1)In terms of morphological indicators,the plant height and stem diameter of each treatment from seedling stage to filling stage increased with the going-on of with the going-on of growth period,but decreased with the going-on of maturity stage.The leaf thickness of each treatment increased first and then decreased with the going-on of growth period,and reached the maximum value at the tassel stage.Compared with the traditional planting,changing the planting pattern is beneficial to the development of vegetative organs.(2)Under different planting patterns of maize,the value of photosynthetic effective radiation in canopy at different positions in different periods gradually decreased from top to bottom;the photosynthetic effective radiation in the middle and lower layers of different positions in different treatments generally decreased with the growth period,but the photosynthetic effective radiation in the middle layer would increase to a certain extent when it reached maturity;and compared with the traditional planting pattern,changing the planting pattern can make maize population The photosynthetic effective radiation in the canopy increased significantly.(3)In terms of canopy transmittance,in addition to the ridge position at jointing stage,the transmittance in the middle part of maize canopy of JYL planting pattern is lower than that of other planting patterns at different positions in other periods,and the transmittance in the lower part of maize canopy of JYL planting pattern is lower than that of other planting patterns at different positions in different periods.Therefore,compared with traditional planting,changing the planting pattern can make the light transmittance of maize canopy better.(4)In terms of the distribution of different light quality in the canopy,the values of blue light,red light and far red light in the canopy of maize population under different planting patterns in different periods and positions were gradually reduced from top to bottom,and the values of the upper and middle layers were significantly higher than those of the lower layers;In addition,the distribution of different light quality in the canopy is more reasonable for the planting mode with more photosynthetic effective radiation and better light transmittance.(5)With the going-on of the growth period,the SPAD value of each treatment increased first and then decreased,the SPAD value of DLSH and SBK reached the maximum in the grouting period,The SPAD value of EBK and JYL reached the maximum in the period of tassel;the planting patterns of DLSH and SBK were better in jointing stage and grouting stage,and those of SBK and EBK were better in tassel stage;in the mature stage,the SPAD value of JYL was significantly higher than that of other planting patterns due to the higher leaf thickness.(6)In terms of chlorophy Ⅱ fluorescence parameters,for photosynthetic activity,DLSH performed better than other planting patterns at jointing stage,EBK performed better at tasseling stage and filling stage,EBK and DLSH performed better at maturity stage,while JYL performed worse than other planting patterns;in terms of light energy conversion efficiency and actual light energy acquisition efficiency,DLSH performed better at jointing stage,and the photosynthetic efficiency of EBK and SBK in tassel stage,filling stage and maturity stage is better,while JYL is lower than other planting patterns in light energy conversion efficiency and actual light energy acquisition efficiency;the light protection ability directly affects the light damage of maize,the light protection ability of SBK was better in jointing and filling stage,EBK was better in tasseling stage,JYL is better in mature stage because of its good leaf thickness in mature stage.(7)The yield of maize is DLSH >EBK > JYL > SBK;the Ear length is DLSH>SBK>EBK>JYL;the barren tip length is SBK > EBK > JYL > DLSH;the spike width is DLSH > EBK > JYL > SBK;the cob weight is DLSH > JYL > EBK > SBK;the kernels per cob is EBK > DLSH > JYL > SBK;the grain weight per panicle is EBK > SBK > DLSH > JYL;the dry matter weight is EBK > SBK > DLSH > JYL;the rainfall utilization rate is EBK > SBK > DLSH > JYL.