| Flue-cured tobacco,as an industrial raw material crop,is one of the bulk agricultural products of Heilongjiang trade.In recent years,in order to achieve the maximum benefit of the flue-cured tobacco economy,the excessive application of chemical fertilizers has caused serious soil degradation in the black soil tobacco area.The productivity of soil in tobacco areas is imperative.In this experiment,the Heilongjiang Binxian soil type was used as the test site,and Longjiang 911 was used as the flue-cured tobacco type.The plant rhinoceros(annual)(Melilotus officinalis L.)and wheat(Triticum aestivum L.)were used as green manure varieties.Field trials were adopted,through 7 processes(Y1-intercropping rhinoceros+nitrogen reduction 30%fertilization;Y2-intercropping rhinoceros+no fertilizer application;Y3-intercropping wheat+nitrogen reduction 30%fertilizer;Y4-intercropping wheat+no fertilizer application;Y5-no Intercropping with green manure+conventional fertilization;Y6-no intercropping with green manure+30%nitrogen reduction fertilization;CK-without intercropping with green manure+no fertilization)The effects of two green manure and intercropping with previous crops on the soil nutrients and soil enzyme activities,the growth physiological characteristics of flue-cured tobacco,the chemical composition of tobacco leaves,and economic traits were investigated.The main results of the study are as follows:1.Intercropping green manure affects soil nutrients and soil enzyme activity in tobacco fields.Intercropping rhinoceros+nitrogen reduction 30%fertilization treatment(Y1)has a good promotion effect on cracking the nitrogen content of the soil at different development stages of flue-cured tobacco;Y3 treatment has a higher available phosphorus content in the first and middle stages of flue-cured tobacco growth;The catalase activity and invertase activity,Y4 has a significant effect on promoting soil urease and phosphatase activities.2.Intercropping green manure affects the growth characteristics and economic properties of flue-cured tobacco.Y3 at the tuft stage can significantly increase the leaf number,plant height,stem circumference,leaf length and leaf area of flue-cured tobacco.The green manure in the flat-top period can promote the agronomic traits of tobacco plants to a certain extent;It has obvious promotion effect;Yl and Y3 can increase the single leaf weight,yield and output value of flue-cured tobacco,which are increased by 24.89%,31.875%,34.62%compared with CK.3.Intercropping green manure affects the physiological characteristics of flue-cured tobacco.Yl and Y3 can improve the net photosynthetic characteristics and SPAD value of flue-cured tobacco,and the leaf area coefficient(LAI)is preferably Y2 and Y4.According to the grey correlation and correlation analysis,it can be seen that the physiological characteristics of flue-cured tobacco are the dominant factors,which affect the economic characteristics of flue-cured tobacco and the coordination of tobacco leaf chemical components.4.Intercropping green manure affects the accumulation of nutrients in different parts of flue-cured tobacco.The content of chlorine and total nitrogen in green nutrient treatment in different vegetative organs is relatively high,and there is no significant difference between treatments.Y1 and Y3 can increase the potassium content in roots,stems and leaves.The total phosphorus content showed that Y1 treatment increased the total phosphorus content in the roots and leaves,and Y4 treatment increased the total phosphorus content in the stems.5.The effect of intercropping green manure and chemical fertilizer on the main chemical components of flue-cured tobacco leaves.For the analysis of the main chemical composition of flue-cured tobacco,Y4 has a better overall effect on increasing the content of nicotine,potassium,total nitrogen and total phosphorus;the content of reducing sugar and sugar-base ratio is preferably Y3.According to the tobacco chemical composition coordination score and weight assignment evaluation,Y1 and Y3 can improve the coordination of C3F and X2F grades of tobacco leaves,improve the economic benefits of flue-cured tobacco,and also have a good effect on improving soil fertility.In summary,from the perspective of green sustainable development,intercropping green manure can replace the effect of some chemical fertilizers.For the black soil tobacco area of Heilongjiang,intercropping as green fertilizer+nitrogen reduction 30%fertilization treatment(Y1,Y3)is more suitable. |
