Effects Of Horizontal Structure On Canopy Vertical Structure、 Light Distribution And Yield Of Winter Wheat

The horizontal distribution of crops in the field directly affects the characteristics of the canopy structure,resulting in differences in light distribution,photosynthesis characteristics and photosynthetic products in the canopy.At present,20 cm equal row spacing planting mode is still the main mode in the large-scale production of winter wheat.Therefore,in order to make full use of the light resources per unit land area,tap the photosynthetic potential of crops and improve the yield of crops,In this experiment,traditional equal row spacing(R1,20cm+20cm),wide and narrow rows(R2,12cm+12cm+12cm+24cm)are set.Two different row spacing and low(D1,120kg·hm-2),medium(D2,157.5kg·hm-2),high(D3,195kg·hm-2)three horizontal structure configuration combinations for sowing rates,The agronomic traits,vertical canopy structure,canopy PAR distribution and utilization,population photosynthetic capacity,biomass and yield performance of winter wheat at different growth stages under each treatment combination were analyzed.The purpose was to explore how to improve wheat brightness without increasing water and fertilizer input.The main research results of green cultivation techniques and ecological mechanisms for energy utilization and yield are as follows:The horizontal structure configuration has an important influence on population dynamics,tiller number per plant and LAI of winter wheat.Under the same row spacing configuration,the tiller number of winter wheat population increased with the increase of sowing rate,while the tiller number per plant,tiller ear rate and total ear rate decreased with the increase of sowing rate,and the differences among sowing rates were significant;during the wintering to flowering period,Lai of Winter Wheat showed D3>D2 > D1 with the increase of sowing rate,and D2 > D3 > D1 from 10 d to 30 d after flowering,and the differences among different sowing rates were significant.Under the same sowing rate,the tiller number of population,tiller number per plant,tiller ear rate and total ear rate among row spacing showed R2 > R1,but there was no significant difference between row spacing.The Lai between two row spacing showed that R2 was significantly higher than R1 from anthesis to 20 days after anthesis.The horizontal structure configuration significantly affected the vertical structure of winter wheat canopy.In the same row spacing configuration,DIFN of each layer decreased with the increase of seeding rate,in which DIFN of middle and upper layer of canopy had significant difference among different seeding rates,while that of lower layer only had significant difference between D1 and D3;MLA of upper layer increased with the increase of seeding rate,while that of middle and lower layer increased with the increase of seeding rate The MLA of D2 was significantly higher than that of other sowing rates.Under the same seeding rate,DIFN and MLA of R2 row spacing configuration were higher than that of R1,especially DIFN and MLA of middle and upper layer.There were significant differences in the vertical distribution and photosynthetic capacity of wheat under different horizontal structure.Under the same row spacing,the interception rate and percentage of PAR and total par interception rate in the upper layer of winter wheat canopy increased with the increase of the sowing amount(10 days after flowering),while the interception rate and proportion of PAR in the middle layer decreased with the increase of the sowing amount;the photosynthetic potential(LAD),the PAR conversion rate(PCE)and PAR utilization rate(PUE)of winter wheat were both in the flowering stage and maturity stage,with the largest D2 sowing amount,and the difference of the sowing quantity was significant;The canopy photosynthetic rate(CAP)and Flag Leaf SPAD value reached the maximum at flowering stage and 10 days after anthesis,respectively.At jointing stage,the CAP of winter wheat showed D3 >D2 > D1 with the increase of sowing rate,while at booting stage,it showed D2 > D3 >D1,and it showed D2 > D1 > D3 after anthesis;SAPD of winter wheat increased with the increase of sowing rate from booting stage to 10 days after anthesis,and it showed D2 > D3 > D1 from 20 to 30 days after anthesis.Under the same sowing rate,the interception rate and proportion of lad,PCE,PUE and PAR in the middle layer of winter wheat were R2 > R1,especially from flowering to maturity,while the interception rate and proportion of par in the upper layer were significantly higher than R2;the CAP and SPAD values of winter wheat were significantly higher than R1 in row spacing of R2 after flowering.The effects of different levels of structure on winter wheat biomass,yield and yield components were significant.Under the same row spacing configuration,the leaf biomass(BL)and spike number of different layers of winter wheat increased with the increase of sowing rate.There was no significant difference in spike number between D2 and D3,but the biomass per plant(BP),grain number per spike and 1000 grain weight decreased significantly with the increase of sowing rate.Therefore,the grain yield of winter wheat was the highest in D2: 8835 kg · hm-2,the second in D3: 8692 kg · hm-2,and the lowest in D1: 8363 kg · hm-2.Under the same sowing rate,BL and BP of R2 row spacing configuration at different levels were higher than that of R1,especially under D2 and D3 sowing rates;There was no significant difference between row spacing in spike number,but in grain number per spike,1000 grain weight and grain yield,R2 row spacing configuration was significantly higher than R1 row spacing configuration.In conclusion,according to the results of this experiment,considering the agronomic characters,vertical structure of canopy,par distribution,utilization of light resources and yield of different horizontal structure configuration,the combination of R2(12:12:12:24 cm)row spacing mode and D2(157.5 kg · hm-2)sowing rate was the best.