Study On Canopy Structural Characteristics Of High Yield Intercropping Maize

Reasonable crop canopy structure is conducive to capturing photosynthetic effective radiation,reducing light leakage loss,and fully alleviating the contradiction between individuals,and achieving the synergetic gain between individuals and groups,which is the main reason for narrowing the crop yield gap and comprehensively increasing yield.In this study,through the investigation and analysis of the high-yield fields in the three main intercropping maize production areas in southern,central,and northeastern in Sichuan,and using the intercropping farmers cultivation pattern and monoculture as the control,under the comprehensive measures of reasonable dense planting and integrated management of water and fertilizer Based on the formed super-high-yield cultivation model of intercropping,the canopy structure characteristics,photosynthetic characteristics,material accumulation characteristics,yield and root distribution characteristics of super-high-yielding maize under inter-cropping system were systematically studied,and the intercropping super-high-yielding maize canopy structure was formed Eigenvalues.The main results of this study are as follows:1.Maize yield distribution and corresponding canopy structure characteristics in high-yield intercropping fieldsThe yield and canopy structure of the high-yield fields in the main intercropping maize production area in Sichuan were investigated over three continuous years,the result indicated that the highest yield of intercropped maize could have 10967.67 kg hm^-2,and the yield distribution of 90 high-yield fields were analysed by normal statistical of law,which showed that 20%of the field yield reached the super-high yield level of intercropping maize over 9000 kg hm^-2.Under the intercropping super-high-yield cultivation model,the 2 year yield of maize reached 9021.50 kg hm^-2 and 10476.93 kg hm^-2,respectively,which have all achieved the goal of super-high-yielding intercropping maize.The corresponding canopy structure characteristics of intercropping high-yield maize are:plant height 260 cm～309 cm,stalk height 100 cm～153 cm;leaf area index in the silking stage 4.58～5.58,and leaf area index in the mature stage 2.91～4.34;The dry matter accumulation in the silk stage was 7370.71 kg hm^-2～7853.28 kg hm^-2,and the dry matter accumulation in the mature stage was 16411.24 kg hm^-2～17842.65 kg hm^-2.2.Canopy structure characteristics of intercropping super-high-yield maizeThe results of a two-year field control experiment showed that the intercropping super-high-yield maize has a plant height in the range of 270 cm～310 cm,which is significantly lower than that of monoculture super-high-yield,but it is significantly increased by 6.89%to 9.18%compared to the intercropping farmers.The average leaf angle on the bar three leaves was 22.48°,which was 11.29%lower than that of the intercropping farmers cultivation pattern;the average leaf angle of ear leaves was 26.51°,which was significantly lower than the monoculture high-yield and intercropping farmers cultivation pattern;The LOV was 64.2,which was a significant increase of 19.15%compared to the intercropping farmers cultivation pattern.The average LOV of ear leaves was 56.98,which was significantly higher than that of monoculture high-yield and intercropping farmers.The intercropping super-high-yield maize had a maximum leaf area of 5.66,the farmer cultivation pattern was only 3.82,the monoculture super-high-yield maize had an average area index of 5.99.In maturation stage,the intercropping super-high-yield maize had an average leaf area index of 3.44,and the farmer’s maize had an average leaf area of2.80,the average leaf area index of monoculture super-high-yield maize was 2.93,and the decline rate of the intercropped super-high-yield leaf area index was significantly lower than that of monoculture super-high-yield.The intercropping super-high-yield maize before flowering had a LAD of 104.16×104m²d hm^-2,which was significantly lower than the monoculture super-high-yielding,but significantly increased by 45.41%compared with the intercropping farmers’maize;significantly higher than the net high-yield and intercropping farmers.There was no significant difference in the photosynthetic production capacity of intercropping super-high-yield maize after flowering and monoculture super-high-yield,but it was significantly increased by 60.99%compared with the intercropping farmers’maize.After flowering,the LAD reached 262.22×104m² d hm^-2,which was significantly higher than the monoculture high-yield and intercropping farmers’mazie.There was no significant difference in the photosynthetic production capacity of intercropping super-high-yield mazie after flowering and monoculture super-high-yield,but it was significantly increased by 60.99%compared with the level of intercropping farmers’maize.The average light transmittance of the intercropping super-high-yield maize ear and bottom are 27.83%and 18.27%respectively.Compared with the monoculture super-high-yield maize,the transmissivity of the ear layer is significantly improved,and the light energy interception rate is significantly reduced.The activities of Ru Bp Case,PEP Case,and SOD in the below the ear leaves were significantly increased by 6.93%,20.62%,and 23.61%,respectively,and the biomass of the root was significantly reduced by 19.39%;compared with the farmers’maize,the transmittance of the ear was significantly reduced by 31.86%,and the light energy intercept rate was significantly increased by 29.69%,the Ru BPCase activity of the upper,middle and lower leaves was significantly increased by33.98%,8.71%and 14.19%,the PEPCase activity was significantly increased by 6.94%,11.81%and 6.94%respectively,and the SOD activity of the middle and lower leaves was significantly increased by 8.48%,11.64%,the biomass of the canopy root increased significantly by 109.88%.3.High-yield mechanism of intercropping super-high-yield maize canopy structureUnder the intercropping super-high-yield cultivation,the maize leaf has a low leaf angle and a large LOV,which forms an ideal plant type and builds a reasonable group structure.The light interception rate of the ear leaves is significantly increased by 29.69%,which improved the maize canopy light energy utilization.The leaf area index at the silking stage reached 5.66,which provided sufficient photosynthetic sources for the production of photosynthetic substances before flowering.The SOD activity of the middle and lower leaves after silking was significantly increased by 8.48%and 11.64%respectively,which improved the anti-aging ability of the leaves and delayed the leaves.The senescence rate and effective photosynthetic leaf area last for a long time,prolonging the active period of grain filling,resulting in a significant increase in dry matter accumulation after flowering by 45.27%.Under the condition of sufficient water and fertilizer,the canopy roots of intercropping super-high-yield maize are mainly distributed in the shallow surface of 0-10 cm,which is conducive to exerting the competitive advantages of individual corn roots and promoting the absorption of nutrients and water by the roots.In addition,the intercropping super-high-yield cultivation pattern significantly increased the corn root biomass by 109.88%,and the robust root system provided sufficient nutrients for the aboveground.The reasonable canopy structure of intercropping super-high-yield maize has achieved synergetic gains above and below ground,which is the main reason for achieving the target yield.Under the intercropping cultivation pattern,insufficient leaf area before flowering and low light interception rate are the main reasons that the yield of intercropping super-high-yielding mazie is significantly reduced by 9.15%compared with monocultuer super-high-yielding maize Therefore,measures such as properly adjusting the row spacing of intercropped corn,coordinating nutrient management,and creating good arable layers to improve the anthesis leaf area and light energy interception rate are the effective ways to reduce the monoculture and intercropping mazie yield gap.At the same time,proper densification and strengthening of nutrient management on the basis of the existing farmer cultivation pattern can build an ideal canopy structure to increase the effective ear and leaf area index,to achieve the purpose of reducing the yield difference,which is an effective measure to achieve super high yield of intercropping maize.