| In this experiment,corn/alfalfa intercropping was carried out,and single crops and intercropping with 30 cm,50 cm,and 70 cm corn rows were set,and a total of 7 treatments were used for the alfalfa row spacing of 30 cm.The soil nutrient and enzyme activities of the seven treatments were studied.Plant growth effects and screening out combinations that are available for actual production options.The results show:1.When the corn was used alone,the total nitrogen content in the heading stage and the waxy stage was lower than that in the filling stage,with a decrease of 0.58%~2.34%.The total phosphorus content in the soil during the filling stage was lower than the heading stage and the waxing stage,with a decrease of 5.63%~10.71%,5.13%~7.41%;the soil alkali nitrogen content in the waxy maturity period was lower than the heading stage and the filling stage,and the decrease was 4.12%~12.67% and 1.88%~8.06%,respectively.When alfalfa was used alone,the total phosphorus content in the heading stage and waxy stage was lower than that in the filling stage,with a decrease of 1.15%~4.60%.When maize/alfalfa intercropping,the soil available potassium content in the filling stage was lower than the heading stage and the wax maturity stage,with the decreases of 3.51%~36.06% and 3.84%~29.67% respectively.2.At the heading stage of corn: soil urease activity of JZY30,JZY50 and JZY70 decreased by 14.20%,42.92% and 47.21% respectively;soil invertase activity increased by 47.41%,67.98% and 99.13% respectively,compared with DZ30;soil hydrogen peroxide The activity was reduced by 4.68%,8.39%,and 6.94%,respectively,than DZ30.At the grain filling stage of maize: soil sucrase activity of JZY30,JZY50 and JZY70 was increased by 57.44%,59.18% and 31.11%,respectively,compared with DZ30.The soil acid protease activity of JZY70 was 1.67% higher than that of DY70.Principal component analysis showed that the soil fertility was the best when alfalfa was used alone,and the soil fertility was the best when the corn row spacing was 70 cm and 30 cm respectively.3.The total biomass of the intercropped ground was higher than that of the single row under the same row spacing,and the total aboveground biomass of JYZ30 and the total dry weight of the ground of JZY50 were the largest.The land equivalent ratio(LER)of corn/alfalfa intercropping was greater than 1,and the LER increased by 28%,33% and 23% respectively,with the increase of intercropping.The grain yield and biomass of maize intercropping were higher than that of single crop,and increased with the increase of row spacing.The biomass and dry weight of the first alfalfa were higher than that of monoculture,and the second crop was generally lower than monoculture.The intercropping competitiveness of corn increased and then decreased with the increase of row spacing,and the productivity of intercropping system increased with the increase of row spacing.The intercropping advantage increased and then decreased with the increase of row spacing.4.The plant height and stem diameter of intercropped maize were generally lower than that of monoculture.The plant height and stem diameter of intercropping and monoculture increased first and then decreased with the growth period.The crude fiber and coarse ash of corn intercropping were generally higher than that of monocropping and crude protein.Ether extract and nitrogen-free extracts are generally lower than monoculture.The content of crude fiber and crude protein in alfalfa was lower than that of intercropping,and the content of coarse ash,ether extract and nitrogen-free extract was generally higher than that of intercropping;the content of crude alfalfa was higher than that of intercropping.Protein,crude ash,ether extract and nitrogen-free extracts were generally lower than intercropped.Through the gray correlation comprehensive evaluation,it is concluded that the biological characteristics of the intercropping JZY50 are better than other treatments. |
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