| Soybean is an important oil crop in our country.At present,there is a serious shortage of soybean in our country.The strip intercropping of soybean and maize is an important way to increase the self-sufficiency rate of soybean.It is very important to choose suitable field allocation to increase crop yield and farmers’income in soybean and maize strip intercropping planting mode.The experiment was conducted in Fangsi Town,Yucheng City,Shandong Province in 2022.Under the soybean and maize strip intercropping system,seven row ratio configurations（M represents maize,S represents soybean）were set up,which were 2M2S,2M4S,2M6S,3M4S,3M6S,3M6S’,4M6S,respectively.Intercropping crop yield,yield components,dry matter accumulation and distribution,plant morphology,crop competition and system economic benefits were studied.The test results are as follows:1.Crop yield and yield components,dry matter accumulation and distribution in different field configurations were as follows:maize yield of 2M2S was the highes(8098.13 kg·ha-1)t,and the difference was not significant compared with monocropping.2M6S had the highest soybean yield(1828.80 kg·ha-1).The maize yield of each configuration was SM>2M2S>2M4S>3M4S>2M6S≈4M6S>3M6S>3M6S’.The average yield of each row of maize was as follows:2 rows of maize yield（except 2M6S）>3 rows of maize yield≈4 rows of maize yield>3 rows of maize yield>4 rows of maize yield.In each configuration,the yield of soybean from the side row to the middle row gradually increased;with the increase of soybean rows,the yield of each row of soybean increased.The hundred grain weight of maize in 2M2S was higher than that in other configurations,and the number of grains per plant of soybean in 2M6S was higher than that in other intercropping configurations.The number of grains per plant of maize in 2M4S was higher than that in other configurations.The hundred grain weight of maize was not significantly different from that of 2M2S.The hundred grain weight of soybean was higher than that of other configurations.In soybean R5 stage,2M2S had the highest dry matter allocation ratio in main stem and 2M6S branched stem.In stage R7,the proportion of dry matter in pod grains on main stems and branches of 2M6S was the highest in all intercropping configurations.2.The effects of different field configurations on the morphology and physiology of soybean and maize were as follows:Among all the intercropping configurations,2M6S configuration had the largest leaf area and LAI,the largest stem diameter,and the largest number of branches.The plant height and stem diameter of 4M6S soybean were the least,and the number of main stem nodes was the least.2M2S has the highest plant height.From soybean edge row to middle row,soybean bottom pod height of each configuration gradually decreased,and branch number gradually increased.Under the condition of the same number of maize rows,increasing the number of soybean rows can reduce the height of soybean bottom pod,increase the number of soybean branches and increase the chlorophyll content of soybean.2M4S maize had the highest plant height and the largest stem diameter,while 2M6S maize had the smallest stem diameter.3.Effects of different field configurations on land equivalent ratio,economic benefits and crop competition in the system:The 2M4S configuration had the highest land equivalent ratio（1.44）and the highest economic benefit.The land equivalent ratio of each allocation was in descending order:2M4S>2M6S>3M4S>2M2S>3M6S’≈3M6S>4M6S.The competition index（Km）of maize under intercropping was greater than 1,indicating that maize was in intercropping advantage.Soybean competition index（Ks）is less than 1,and soybean is at a disadvantage of intercropping.The Km of 2M2S was the largest,indicating that the competitive advantage of maize was the largest under this intercropping mode.The relative yield loss（AYLm）of maize in all intercropping configurations was greater than 0,indicating that the yield of maize was higher than that of monoculture.The relative yield loss of soybean was less than 0,indicating that the yield of soybean was lower than that of monoculture.The relative yield loss（AYL）of 2M2S,2M4S,3M4S and 4M6S was greater than 0,indicating that these configurations increased the yield of monoculture.In conclusion,2M4S configuration has the highest land equivalent ratio and economic benefits,which is the recommended configuration for this study. |
