| Different field configurations promote the intercropping system to form different light environments,change the plant morphogenesis of crops,and then affect the light energy utilization and system yield of crops.Northwest China has abundant light and heat resources,which has a natural climatic advantage for the promotion of maize-soybean strip intercropping mode.In order to clarify the response of maize-soybean light energy interception,light energy utilization,morphogenesis,dry matter accumulation and yield to different field configurations under intercropping mode in this area,this experiment was carried out.In this experiment,a two-factor completely randomized experimental design was used to study the interaction of different maize density and bandwidth(treatment included A1:bandwidth 2.2 m,row ratio 2:3,maize density 60000 plants/hm~2;A2:bandwidth 2.5 m,row ratio 2:4,maize density 60000 plants/hm~2;A3:bandwidth 2.8 m,row ratio 2:5,maize density 60000 plants/hm~2;B1:bandwidth 2.2 m,row ratio 2:3,maize density 75000 plants/hm~2;B2:bandwidth 2.5 m,row ratio 2:4,maize density75000 plants/hm~2;B3:bandwidth 2.8 m,row ratio 2:5,maize density 75000 plants/hm~2;C1:bandwidth 2.2 m,row ratio 2:3,maize density 90000 plants/hm~2;C2:bandwidth 2.5 m,row ratio 2:4,maize density 75000 plants/hm~2;C3:bandwidth 2.8 m,row ratio 2:5,maize density 75000 plants/hm~2)on maize and soybean light interception rate,light use efficiency,photosynthetic capacity,agronomic traits,dry matter accumulation and yield formation.On this basis,three corresponding density monoculture maize(CKA:60000 plants/hm~2)were set up;CKB:75000 plants/hm~2;CKC:90000plants/hm~2)and monoculture soybean(CKS)as control.The main results are as follows:1.Effects of different field configurations on crop light interception and utilizationThe light interception rate of maize showed a trend of increasing first and then decreasing in the V5-R3 period,and reached the maximum in the R1 period.When the bandwidth increases,the light interception rate per unit land area decreases significantly,and when the density increases,the light interception rate increases significantly.The average value of the two years is as follows:A1(0.48)>A2(0.44)>A3(0.39),B1(0.54)>B2(0.48)>B3(0.45),C1(0.53)>C2(0.51)>C3(0.49).The light energy interception rate of soybean is affected by the interaction of corn density and bandwidth change.The trend is that the bandwidth increases,the light energy interception rate increases,the density increases,and the light energy interception rate decreases.The light use efficiency rate of maize continued to increase during the V4-R3 period.In the R3 period with the highest light energy utilization rate,the light energy utilization rate increased with the increase of bandwidth.The two-year average performance was:A1(2.13)<A2(2.24)<A3(2.37),B1(2.23)<B2(2.31)<B3(2.42),C1(2.41)<C2(2.42)<C3(2.48).There was no significant difference between different treatments under the same maize density.The light energy utilization rate of soybean reached the maximum value in the R3 period of 2021 and the R5 period of 2022 respectively,and the change trend between treatments was consistent.Under the condition of low corn density,the light energy utilization rate continued to decrease with the increase of bandwidth.Under the condition of medium corn density,the light energy utilization rate decreased first and then increased with the increase of bandwidth.Under the condition of high corn density,the light energy utilization rate continued to rise with the increase of bandwidth.In the R3 period of 2021:A1(1.44)>A2(1.15)>A3(1.12),B1(1.64)>B3(1.48)>B2(1.38),C3(2.13)>C2(1.96)>C1.91),except for the difference between A2 and A3,C2 and C1,the difference between the other different bandwidth treatments was significant.In the R5 period of 2022:A1(2.29)>A2(2.11)>A3(1.93),B1(2.68)>B3(2.51)>B2(2.42),C3(3.42)>C2(3.24)>C1(2.75),there were significant differences among different bandwidth treatments under the same maize density.Under the same maize density,the photosynthetic rate,stomatal conductance,intercellular carbon dioxide concentration and transpiration rate of maize decreased with the increase of bandwidth.Under the same bandwidth conditions,except for intercellular carbon dioxide concentration,the other photosynthetic parameters showed a decreasing trend with the increase of maize density.The photosynthetic rate was:A1(28.27)>B1(27.37)>C1(26.76),A2(26.86)>B2(26.29)>C2(24.51),A3(24.09)>B3(23.79)>C3(23.57).The photosynthetic rate,stomatal conductance and transpiration rate of soybean increased with the increase of bandwidth under the same maize density.The photosynthetic rate of A1,A2 and A3 treatments decreased by 40.55%,25.59%and17.4%respectively compared with CKS,B1,B2 and B3 decreased by 30.79%,29.06%and 10.31%respectively compared with CKS,C1,C2 and C3 decreased by 26.77%,33.07%and 10.31%respectively compared with CKS.2.Effects of field configuration on crop morphogenesis and dry matter accumulationThe stem diameter and leaf area index of maize were significantly affected by the change of density.The stem diameter decreased with the increase of density,while the leaf area index showed the opposite trend.When the maize density was fixed and the bandwidth increased,the dry matter accumulation of maize showed a downward trend.Compared with CKA,A1,A2 and A3 were significantly reduced by 19.93%,23.77%and24.05%,respectively.Compared with CKB,B1,B2 and B3 were significantly reduced by11.64%,17.96%and 18.81%,respectively,compared with CKC.C1,C2 and C3 were significantly reduced by 10.19%,16.06%and 20.04%,respectively.The plant height of soybean decreased,stem diameter,leaf area index and dry matter accumulation increased.The data of R5 period showed that compared with CKS,A1,A2 and A3 treatments significantly decreased by 47.99%,47.67%and 42.67%respectively,B1,B2 and B3significantly decreased by 51.69%,45.24%and 42.03%respectively,C1,C2 and C3significantly decreased by 62.64%,53.62%and 48.47%respectively.The two-year data showed that the maximum dry matter accumulation of C1 and C2 treatment systems with maize density of 90000 plants/hm2,bandwidth of 2.2m and 2.5m was 24.526.42t/hm~2and 28.3425.99t/hm~2,respectively.3.Effects of field configuration on crop yieldThe change of maize density significantly affected the effective ear and grain number per ear.The effective ear increased with the increase of density,and the grain number per ear decreased with the increase of density.Compared with CKA,A1,A2 and A3 decreased by 8.35%,10.57%and 14.08%respectively.Compared with CKB,B1,B2 and B3decreased by 10.05%,11.22%and 16.95%respectively.Compared with CKC,C1,C2and C3 decreased by 6.79%,10%and 12.11%respectively.The effective plant number and grain number per plant of soybean increased with the increase of bandwidth,and the100-grain weight decreased with the increase of maize density.The effects of bandwidth and density on yield,land equivalent ratio,population output value and monetary advantage index were significant or extremely significant.When the bandwidth is constant,the corn density increases from 60000 plants/hm2 to90000 plants/hm2,and the corn yield also increases significantly.The average increase of the two years of monoculture is 19.06%and 17.11%,and the average increase of the two years of intercropping is 14.39%and 28.22%.Expanding the bandwidth was beneficial to the increase of soybean yield.Compared with the 2.2 m bandwidth,the average increase of soybean yield in the two years of the bandwidth of 2.5 m and 2.8 m was 21.46%,29.66%and 15.15%,23.63%.At the same time,soybean yield was also significantly affected by the change of corn density,which showed that the density of corn increased and the yield of soybean decreased.The land equivalent ratio of the intercropping system was greater than 1.25～1.34,and the trend was roughly as follows:with the increase of maize density,the land equivalent ratio increased,the bandwidth increased,and the land equivalent ratio increased first and then decreased.The population output value and monetary advantage index increased significantly with the increase of maize density,and increased first and then decreased with the increase of bandwidth.Based on the two-year data,the northwest region is more suitable for the maize-soybean strip intercropping mode with a maize density of 90000 plants/hm~2and a bandwidth of 2.5 m.The two-year average system yield and population output value are18310.22 kg/hm~2 and 56690.95 yuan/hm~2,respectively. |
PDF Full Text Request