| In order to raise the production and ecological benefits of maize-soybean intercropping under the full mechanization condition,this study adopted maize variety Denghai 605 and soybean variety Hedou 19 as test varieties.In Xuchang,2017-2018,with the rows ratio of maize and soybean was 2:4 in intercropping(2/4I,the width of maize was 3.2m)and the rows ratio of maize and soybean was 4:4 in intercropping(4/4I,the width of maize was 3.2m)as the study objects,with maize monoculture(MM)and soybean monoculture(SM)as the controls.From input and output of crop yield,farmland and soil in greenhouse gas emissions etc.to study the corn crop yield soybean intercropping mode characteristics,soil characteristics and may affect the mechanism of greenhouse gas emissions.At the same time,reasonable intercropping mode of row ratio was selected from 2/4I and 4/4I modes.The main research results are as follows:1.Compared with maize monoculture and soybean monoculture,maize-soybean intercropping significantly improved farmland economic benefits,and the results were as follows:2/4I>4/4I>SM>MM.(1)The differences in input costs of the farmland system are mainly reflected in fertilizers and pesticides.The differences in fertilizers are mainly reflected in maize,and the differences in pesticides are mainly reflected in soybean.Compared with monoculture maize(MM),the input cost of fertilizer in intercropping was significantly reduced by 2/4I and 4/4I,which were reduced by 1279 yuan.hm-2 and 908yuan.hm-2 respectively.Compared with soybean monoculture(SM),the input cost of pesticide was significantly reduced in both intercropping modes,which reduced by 382 yuan.hm-2 and 300 yuan.hm-2 respectively.Compared with maize monoculture(MM),the cost of 2/4I mode average decrease was 22.27%,and that cost of 4/4I mode average decrease was 15.91%.Compared with soybean monoculture(SM),the input cost of 2/4I mode average decreased was 3.20%,and that cost of 4/4I mode average increased was 6.73%.(2)In the farmland system of the four planting modes,the output value is shown as 2/4I>4/4I>MM>SM,and the economic benefit is shown as 2/4I>4/4I>SM>MM.Compared with maize monoculture(MM)and soybean monoculture(SM),the output value and economic benefit of farmland in the 2/4I mode were significantly improved,with the output value increase was 3030 yuan.hm-2,4012 yuan.hm-2 and economic benefit increase was 44.61%and 35.99%respectively.Compared with MM and SM,the output value of crops in the 4/4I mode increase was 1878 yuan.hm-2 and 2804 yuan.hm-2 respectively.Compared with MM and SM,the economic benefits in the 2/4I mode increased by 29.14%and 21.78%respectively.Compared with the output value and economic benefit between the two intercropping modes,4/4I was less than 2/4I,reducing by 1202 yuan.hm-2 and 12.29%respectively.2.Compared with maize monoculture and soybean monoculture,maize-soybean intercropping significantly increased the material output of farmland system.(1)Maize-soybean intercropping mainly reduced the yield of maize and soybean by reducin g the effective plant number of maize and soybean,but the crop population yield of the farmland system increased,and the crop population yield showed as:2/4I>4/4I>MM>SM.Compared with monoculture maize,the 2/4I and 4/4I models reduced production by 3071 yuan.hm-2 and 2375 yuan.hm-2 respectively.The yield of 4/4I was 9.93%higher than 2/4I.Compared with monoculture soybean,soybean yield of two intercropping modes(2/4I and 4/4I)was significantly reduced,with 1802 yuan.hm-2 and 2380 yuan.hm-2 reduced respectively.Soybean yield of 2/4I mode was 28.94%higher than that of 4/4I mode.The land equivalent ratios of the 2/4I and 4/4I modes are 1.23 and 1.14 respectively.(2)Intercropping reduced plant height and stem diameter of maize,and the influence of 4/4I mode was more significant than the influence of 2/4I mode.2/4I increased leaf area of maize per plant,while 4/4I reduced leaf area of maize.Maize-soybean intercropping increased leaf area index(Lai),decreased SPAD at panicle position and increased photosynthetic rate in maize of intercropping system.Compared with 2/4I,Lai and SPAD at panicle position decreased significantly in maize of intercropping system,while photosynthetic rate increased insignificantly.Compared with monoculture,dry matter accumulation per plant of maize and soybean in 2/4I mode was higher than monoculture,but the difference was not significant.However,in the 4/4I mode,the dry matter accumulation per plant of intercropped maize was lower than that of monoculture maize(MM),and the difference was not significant.Compared with the monoculture system,2/4I mode increased the yield per plant of maize and soybean by 12.87%and 18.83%respectively,while 4/4I mode reduced the yield per plant of maize by 1.48%and increased the yield per plant of soybean by 18.73%on average.3.Compared with monoculture maize and monoculture soybean,intercropping can reduce greenhouse gas emission of farmland soil,but the effect is small.Compared with monoculture maize,intercropping reduced CO2 emission fluxes was 2.32 mg.m-2.h-1 and N2O emission fluxes was 0.009 mg.m-2.h-1,respectively.Compared with monoculture soybean,intercropping increased CO2 emission flux was 9.36mg.m-2.h-1 and reduced N2O emission flux was 0.002mg.m-2.h-1.Compared with monoculture maize,intercropping significantly reduced the N2O emission flux of farmland soil was 34.13%at the small trumpet opening stage of maize,and soybean monoculture(SM)was significantly lower than that of maize monoculture(63.81%).Compared with soybean monoculture,intercropping significantly reduced soil N2O emission fluxes and reduced soil N2O emission fluxes was 73.11%in the mature stage of maize and soybean,and significantly reduced soil N2O emission fluxes and reduced soil N2O emission fluxes in maize monoculture field was 79.53%.Soil CH4 emission flux in the soybean monoculture mode(SM)was significantly lower than that in the maize monoculture mode(MM)at the mature stage of maize and soybean,which decreased was 34.01%.However,there was no significant difference in soil CO2 emission flux.Comprehensive the above results,compared with the monoculture of maize and soybean monoculture,maize-soybean intercropping could reduce maize plant height and stem diameter,increase net photosynthetic rate of maize,soybean plant dry matter accumulation and yield of maize and soybeans,and farmland mass production,reduce the use of fertilizers and pesticides,promote farmland crops output and economic benefits,but also reduces the farmland soil in greenhouse gas emissions,both intercropping mode to adapt to the mechanical operation,suitable for promotion in Henan,the rows ratio of maize and soybean was 2:4 in intercropping(2/4I)from all aspects are better in maize and the rows ratio of maize and soybean was 4:4 in intercropping(4/4I). |
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