土壤微生物与连、轮作花生的相互效应研究

STUDIES ON INTERACTIONS BETWEEN SOIL MICROORGANISMS AND SEQUENTIAL CROPPING OR ROTATION OF PEANUT

通过花生在无菌和有菌连、轮作土壤上的栽培效果及连、轮作花生对土壤及根际微生物区系的影响两组盆试验，揭示了土壤微生物对花生生育至关重要，是引起花生连作障碍的主要因子。在灭菌土壤条件下，连作较轮作总生物产量仅减产０．００４％；在有菌土壤条件下，连作较轮作总生物产量减产１０、６８％。花生连作，土壤中的细菌密度较轮作减少３５．４％，放线菌密度减少５４．７％，真菌密度增加１８０．０％，Ｂ／Ｆ显著变小。根际微生物区系的变化与非根际土壤呈同一趋势。连作使土壤由细菌型向真菌型转化。

Two groups of pot experiments were conducted to study effects of succession and rotation in sterilized or unsterilized soil on peanut growth, and effects of succession and rotation of peanut on soil and rhizosphere microflora, The results indicated that soilmicroorganisms were very essential to peanut growth, and they were the major factor causing succession obstacle of peanut. Compared to rotating peanut, yield of sequential cropping peanut only decreced by 0.004% (total biological yield, mean of three yeatg ) insterilized soil. while it decreased by 10.68%(total biological yield, mean of three years ) inunsterilized soil. In comparison to in rotation soil of peanut, denisities of bacteria (B) andactinomyces reduced by 35.4% and 54.7%, respectively, but fungi (F) density increasedwith 180.0%, and B/ F ratio decreased significantly in succession soil of peanut,Rhizosphere microflora and soil microorganisms had the same trend. Succession of peanutcaused soil changing from bacterium type to fungus type.