Effects of potassium fertilizer varieties and combined application on rhizosphere soil microenvironment and rhizomes growth regulation in Paris polyphylla var. yunnanensis(Franch.)

【Objective】To study the effects of two different potassium fertilizers(potassium chloride and potassium sulfate) and the mixture at different proportions on the rhizosphere soil microenvironment of Paris polyphylla var. yunnanensis(Franch.) and provided a scientific basis for the rational application of potassium fertilizers in the cultivation of P.polyphylla var. yunnanensis(Franch.).【Method】The rhizosphere soil nutrient content, microbial quantity and soil enzyme activity, and root viability and rhizome potassium content of P. polyphylla var. yunnanensis(Franch.) was observed in present study by pot experiment. No potassium fertilizer during the growth of P. polyphylla var. yunnanensis(Franch.) was as control(CK), and various ratio potassium chloride and potassium sulfate was set as follows:100:0(PF1), 75:25(PF2), 50:50(PF3), 25:75(PF4), and 0:100(PF5).【Result】The pH value was downregulated in alltreatment groups compared with CK. Treatments except PF1 have increased the rhizosphere soil nutrients and soil microbial numbers to varying degrees, the regulation effects of PF4 was the best, the available nitrogen, available phosphorus, available potassium, organic matter, and the bacterianumber increased by 107.98%, 13.95%, 31.32%, 10.81%, 58.93% compared to CK.Except of neutral phosphatase activity in the soil, most fertilization treatments increased the activities of the other six enzymes. Exogenous application of potassium fertilizer improved the root vitality of P. polyphylla var. yunnanensis(Franch.) compared to CK. Potassium content significantly increased in all treatments both in the old rhizomes and new rhizomes(P<0.05, the same below). The potassium content in old rhizomes and new rhizomes of P. polyphylla var. yunnanensis(Franch.) reached the peak value in PF4 treatment, which were increased by 134.57% and 131.13%, compared with CK.【Conclusion】Exogenous application of potassium fertilizer has positive impact on the growth and development of P.polyphylla var. yunnanensis(Franch.) and the rhizosphere soil microenvironment, but different potash fertilizer ratios have different roles in the soil on micro-environment regulation. The effect of potassium chloride and potassium sulfate in the ratio of 25:75(PF4) is the best.