The Study On The Sensitivity To Boron Of The Different Soybean Genotypes And The Efficiency Of Boron Extracted With Different Methods

In recent years, the situation of the reduction of the crop yield is serious owing to the deficiency of boron. The set failure of soybean caused enormous economic loss to farmers in Nehe as well as the nearby regions in Hei Longjiang province in 1999. We can infer that the deficiency of the micronutrient of boron should be responsible for it by the preliminary soil analysis and the investigation of the field. In order to give conduct to the agriculture cultivation, it is urgent to study the sensitivity to the deficiency of boron and the different fractions of boron with the native soybean genotypes. The results showed as follows:1 There were some variances in the plant height and dry matter accumulation among genotypes in certain extent of applying boron. The dry matter accumulation(DMA) was improved in all varieties when applied boron, though the improvement was different in different boron treatments. The variety of North9395 had the greatest DMA( not including the seed) when applied 3Kg/hm2 of boron. The high level of boron was benefit for the dry matter transplant from the other parts of plant to the seeds. However, North454 and North384 got the highest DMA when applied 3 Kg/hm2 of boron, and the seed DMA was also higher.2 there was also an enormous impairment on the yield component factors when applied boron. The pods, seed numbers and seed weight of each plant were all improved when applied boron. The impairment was different among the varieties. North9395 and North454 are sensitive to low soil boron, but North384 was less sensitive. In addition, North9395 had a narrow suitable extent of boron. It would be toxicity when the concentration of soil boron was higher, whereas North454 has a relative broader suitable extent. North384 is a genotype which is not sensitive to low soil boron and had a broad suitable extent.3 The boron content of the tops among different varieties in different treatments of soil boron was mainly expressed in leaves throughout the growth and development of the plant. The boron content of leaves was higher than that of stem in both seedling and flowering period. In leaves, flowering period had a higher boron content than seedling when applied no external boron, however it was on the contrary as to the 3 Kg/hm2 and 4.5 Kg/hm2 of boron treatment. The content of boron in seed was different with the variation of the external boronlevels. North384 had the highest content, which was followed by North454. North9395 had the least content.4 CaCl2-B,KH2PO4-B and NH2OH.HCl-B could reflect well the relation between the capacity of soil supplying boron and plant absorption of boron. KH2PO4-B had the most correlativity with the boron content of the leaves.