Effects Of Cereal-Forage Planting Patterns On Crop Yield And Soil Water And Salt Dynamics In Coastal Saline-alkali Land

In 2018-2019,this experiment was carried out in Yellow River Island,Wudi,Binzhou of Shandong province.In order to explore the effects of different planting patterns on crop yield,economic benefit and soil physical and chemical properties in coastal saline-alkali land,Jimai22,Ludan9066,WL354 were used as experiment materials and set up the wheat and maize(W-M),wheat and maize and intercropping alfalfa(W-M||A)and monoculture alfalfa(MA)as three planting patterns,compares the different planting patterns of crop growth,yield,economic benefits,and soil water and salt dynamics,etc.The main research results are as follows:1 Effects of different planting patterns on physical and chemical properties of coastal saline-alkali soilCompare the changes of soil bulk density about pre-sowing and harvest stage in different planting patterns.In the 0-20 cm soil layer,W-M||A decreased the soil bulk density by 6.52%,in the 40-60cm soil layer,MA decreased the bulk density by 3.25%.In 0-20 cm soil layer of W-M,the total porosity increased by 9.81%,and in 40-60 cm soil layer of MA,the total porosity increased by 13.68%.In the 0-20 cm soil layer,the non-capillary porosity of MA increased significantly by 8.39%,and W-M||A in the 40-60cm soil layer increased significantly by 123.78%.There was no significant difference between the three patterns in soil pH,but soil pH was significantly lower in wheat jointing stage and heading stage.In 0-40 cm soil layer,with the deepening of soil layer,TOC and STN content showed a downward trend.In 0-10 cm soil layer,the TOC of three patterns was the most different significantly.The TOC of MA was significantly higher than that of W-M and W-M||A,20.51%and 25.91%higher respectively.In the 20-40 cm soil layer of corn filling stage,STN difference is the most significant,MA is significantly higher than W-M and W-M||A,65.32%and 63.97%higher than W-M and W-M||A,respectively,MA is conducive to the increase of TOC and STN.2 Effects of different planting patterns on soil water and salt dynamics in coastal saline-alkali landWith the deepening of soil layer,the soil water content in each period showed an upward trend.The soil moisture content of 0-100 cm soil layer decreased from the before wintering to the harvest stage of wheat.The soil moisture content of maize jointing stage was the highest,and gradually decreased with the growth stage.The salt content in the surface soil was significantly higher than that in other soil layers.The C.V.of water and salt content in 0-10cm soil layer is W-M(23.37%)>MA(21.89%)>W-M||A(19.50%),and the C.V.of salt content is W-M(49.04%)>W-M||A(45.89%)>MA(42.64%).The water content of W-M|A in 0-40 cm soil layer from wheat before winter to maize harvest stage is in accordance with the approximate normal distribution,indicating that the water change is relatively stable.The water salt change of W-M||A is the most stable,MA is the second,and W-M is the most unstable.3 Effects of different planting patterns on the growth,yield and quality of crops in coastal saline-alkali landThe plant height,leaf area index and dry matter of intercropping wheat and maize were better than that of monoculture.The net area yield of intercropping wheat is significantly higher than that of monoculture,which is 26.82%higher.The net area yield of intercropping maize is significantly higher than that of monoculture,which is 14.01%higher.The net area yield of monoculture alfalfa is significantly higher than that of intercropping,which is 23.34%higher.The annual yield of W-M is the highest,which is 7680.62 kg/hm~2,followed by W-M||A,which is 6295.73 kg/hm~2,and MA is the lowest,which is 4179.51 kg/hm~2.The land equivalent ratio is 1.00,and there is no intercropping yield advantage.In the first harvest,the EE content of W-M||A is significantly 4.17%higher than that of MA.In the second harvest,the CP,EE and RFV of MA were significantly higher than those of W-M||A,7.34%,7.95%and 6.97%respectively,while the content of NDF in W-M||A was significantly 4.86%higher than that of MA.In the third harvest,the CP,EE and RFV of MA are significantly higher than W-M,which is 6.70%,7.87%and 11.18%respectively.The nutrition and feed quality in MA are better than W-M||A.4 Comparison of economic benefits of different planting patternsThe profit of W-M||A is the highest,4254 yuan/hm~2,followed by W-M,3721 yuan/hm~2,and MA is the lowest,2972 yuan/hm~2.The outcome/cost of MA is the highest,which is 1.59,followed by W-M||A,which is 1.52,and W-M is the lowest,which is 1.32.The W-M||A can significantly improve economic efficiency,and at the same time provide the forage grass needed for the development of animal husbandry,which is conducive to promoting the overall development of agriculture and animal husbandry.The input of fertilizers and pesticides is low,and the water and salt changes in the 0-40 cm soil layer are the most stable,which is conducive to the stability of crop yield and the sustainable use of coastal saline-alkali land.