Relationship Between Crop Growth,Yield And Meteorological Factors In Alfalfa Wheat Intercropping System

Intercropping two or more crops can make full use of land resources,improve the efficiency of crop utilization of climate,water and other resources,reduce the waste of resources,increase crop yield,and contribute to the sustainable development of intensive agriculture and ecological agriculture.In this study,we used winter wheat and alfalfa(Medicago Sativa Linn)in different intercropping patterns as materials,and analyzed the growth and development,SPAD value and yield of crops in both patterns through field observation,sampling and yield measurement,and calculated the growth models of crops in different intercropping patterns.The main results of the study are as follows.(1)In terms of crop growth and development,intercropping of clover-wheat could significantly improve the growth potential of wheat.Except for wheat XM-2 treatment(1 row of alfalfa,2 rows of wheat),the growth potential of winter wheat under intercropping mode was higher than that of monoculture wheat,and the linear growth period was entered earlier and lasted longer.Compared with monoculting alfalfa,the performance of intercropping alfalfa was contrary to winter wheat,and the growth potential of intercropping alfalfa was lower,and the time to enter the linear growth phase was later and the duration was shorter.From the perspective of crop leaf SPAD value,the variation trend of wheat and alfalfa leaf SPAD value under different intercropping modes was different,but different intercropping modes could improve the crop leaf SPAD value,and the crop SPAD value under belt intercropping mode was more advantageous than that under intercropping mode.(2)According to the relationship between plant height,SPAD value and meteorological factors,the regression analysis showed that the lowest temperature had the greatest influence on plant height under different intercropping patterns(R2 BBB 0 0.559,P<0.05).Grey correlation analysis showed that relative humidity and maximum temperature had the greatest influence on leaf SPAD values of alfalfa and winter wheat under the two intercropping patterns,while precipitation had the least influence on SPAD values.(3)From the relationship between winter wheat yield and meteorological factors,relative humidity and maximum temperature had the greatest effects on wheat yield under different intercropping patterns(R= 0.8723,R=0.8709),while precipitation had the least effects(R=0.5008).From the perspective of the period effect of meteorological factors,taking XM-2 as an example,from mid-March to early June in 2018,the relative humidity of each decade had the greatest impact on winter wheat yield in mid-April and late May,while the accumulated temperature in mid-April and late April had a greater impact on wheat.Precipitation in mid-April and mid-March had the greatest effect on winter wheat yield.(4)From the relationship between alfalfa yield and meteorological factors,relative humidity and maximum temperature had the greatest effects on alfalfa yield under different intercropping patterns(R=0.8933,R=0.8504),while precipitation had the least effect(R=0.4603).Taking XM-2 as an example,the relative humidity in early April and early May and the maximum temperature in late April and mid-April had the greatest influence on the yield of the first alfalfa.The maximum temperature in early and middle July and the average temperature in mid-July and early July had the greatest influence on the yield of the second crop.Relative humidity and maximum temperature in mid-August and late July had the greatest influence on the third crop alfalfa yield.