Abstract: In order to screen out the high-yielding kenaf hybrids which are suitable for growing on saline-alkali land in North Henan, taking H318 as a control, we compared 11 traits of six pairs hybrids F₁ and F₂ of kenaf and analyzed the competitive advantages of each trait, the difference and correlations between F₁ and F₂ generations, as well as the fading rates of the generation F₂ relative to F₁. The results showed that significant differences existed in the competitive advantage of each trait among combinations of F₁ and/or F₂ generations. The heterosis of F₂ generations declined significantly, but the heterosis in a few combinations could be exploited. Moreover, there were highly significant positive correlations in fiber thickness, dried rate of fresh fiber and fiber rate of fresh stem between F₁ and F₂ generations. For harvesting the whole stem of kenaf, the F₁ of combination F3A/992 and the F₂ of combination F3A/R7 were the best, but for harvesting the fiber of kenaf, the F₁ of combination P3A/R1 and the F₂ of combination P3A/992 were the best.

Key words: nitrification, site preference (SP)., stable isotope, soil microbe, denitrification