Abstract: With the “xilong” seed-protected agent coating the seeds of wheat,corn,soya,the total number quantity of rhizophere microbes (in various growth stages, espectially in seeding stage) was notably increased, in comparision with uncoated treatment. The experimental data indicated that the amount of the ammounficator physiological group,nitrobacteria physiological group, azotobacter physiological group increased differently. The seed-protected agent promoted rhizosphere microorganisms activity. The intensity of cellulose-decomposition and the intensity of soil respiration rose obviously. As a result the conversion rate of available nutrients was accelerate and contents of soil available nutrients became higher. The crops grew better and the yield increased greatly.

Key words: Dendrobium officinale,  D. nobile,  D. chrysotoxum, partial least square regression,  quality.