A Comparison Of Salt-tolerance, Productivity And Nutritional Quality Between Six Melilotus

Melilotus,a kind of excellent pasture and green manure crop, not only has high yield and outstandingquality, but also shows very strong tolerance or resistance to the adverse environment. The experimentcompared6Melilotus from different area in terms of salt tolerance at germination and seeding stage,productive performances, nutritional quality,as well as the impact on soil,besides,the impact of Melilotuson yield and quality of following crop were studied.Observe the germination in different NaCl salt stress solution concentrations(which were0%、0.3%、0.6%、0.9%、1.2%、1.5%、1.8%),and the influence on germination rate, potentiality of seed,germination index, seed vitality index. The result showed that M1(M. officinalis from Gansu) waspromoted when NaCl solution concentration was0.3%, M6(M. officinalis from Ningxia) was promoted when NaCl solution concentration was0.6%,When NaCl solution concentration beyond0.9%,various varieties were inhibited.When NaCl solution concentration beyond1.2%,The degree of saltinjury was aggravated. Appraising the salt resistance of six Melilotus from different sources synthetically through the method of subordination function,the sequence of salt resistance was M6,M1,M2,M4,M5,M3.The seedings of6Melilotus were treated under salt stress with NaCl solution of differentconcentraions(which were0%,0.3%,0.6%,0.9%).Observe the growth situation,and the content of solublesugar, soluble protein,free proline and malondialdehyde were determined after the emergence of2months.The result shows that the height of all Melilotus reduced gradually along with the higherconcentration of NaCl solution.Meanwhile, the content of soluble sugar, soluble protein and free prolineincreased gradually.The content of free proline of M4and M6increased sharply when NaCl solutionconcentration beyond0.6%. simultaneously, along with the higher concentration of NaCl solution,M3andM6had significantly higher content of the MDA.The other Melilotus,whose MDA content had a slightincrease just when the concentration of NaCl solution was0.3%,then falling slowly. Appraising the saltresistance of6Melilotus from different sources synthetically through the method of subordinationfunction,the sequence of salt resistance in seeding stage was M1,M2,M4,M5,M6,M3.Laboratory and field experiments were conducted to research the difference of production performance and nutritional quality between6Melilotus species from different habitats. We determinedthe biological characteristics,hey yield,crude protein yield and the nutrient composition content of different Melilotus.The result showed that the top cultivar with the highest annual hay yield and annual crude protein(CP) yield were M2(11500kg/hm2) and M1(1729.18kg/hm2),respectively.The sequence of annual hay yield of6Melilotus species is M2,M4,M6,M1,M3,M5, The sequence of annual CP yield is M1,M2,M4,M6,M3,M5.A comprehensive comparison of nutritional quality has been made through compute the grading index(GI),the order of the nutritional value is M3,M5,M2,M4,M1,M6.Soil samples from0～10cm,10～20cm,20～30cm were collected when planted6Melilotus a yearlater.We determined the content of total salt,organic matter,total nitrogen,available nitrogen,rapidlyavailable phosphorus and potassium of soils.Then the impact of6Melilotus on soil was compared.Theresult shows that soil fertility improved effectively after planted Melilotus.M2could reduce the total saltcontent.M1,M6as well as M4could increase the organic matter and total nitrogen content.M1and M6could increase the available nitrogen content of top soil.The content of rapidly available phosphorus had aincrease after planted M4and M6.At the same time,M6could increase each soil nutrient.Choose a sample plot of winter wheat which preceding crops was Melilotus,controlled for a sampleplot of winter wheat which preceding crops was corn. Winter wheat’s grain yield, thousand seed weightand crude protein content were determined,then evaluated the Melilotus impact on following crop.Theresult shows that Melilotus as preceding crops, winter wheat’s grain yield and crude protein content had a highly significant higher than control(P＜0.01),17.23%、34.89%,respectively. Thousand seed weight wasincreased5.05%than control, significantly(P＜0.05).