Abstract:

In order to prove up the soil fertility level of apple, pear, peach and grape orchards in Beijing region, soil samples were collected to analyze the soil physi-chemical properties and microbial populations in three levels of yield and quality orchards (H, M, L). The results showed that soil bulk density, cation exchange capacity (CEC) and pH were 1.06～1.60 g.cm-3, 81.47～238.83 mmol.kg-1 and 7.39～8.55 respectively. Soil bulk density was no significant difference among different fruit trees, the CEC values of apple, peach and grape orchards were significantly higher than pear ones, and H and M orchards were higher than L’s in the same fruit trees. Soil organic matter (SOM) was between 7.34 g.kg-1 and 19.50 g.kg-1, no significant difference among the different fruit trees, and H orchard was higher than M’s and L’s in the same fruit trees. Total nitrogen (N) content of all orchards were between 0.41 g.kg-1 and 1.09 g.kg-1, but apple, peach and grape orchards were significantly higher than pear’s, and H orchard was higher than M’s and L’s in the same fruit trees. Soil available phosphorus (P) and potassium (K) were 14.54～185.50 mg.kg-1 and 99.77～267.50 mg.kg-1 respectively, no significant difference as in the different fruit trees as in the different levels orchards. The soil available iron (Fe), zinc (Zn) and boron(B) community of four fruit trees was 0.45×107～1.23×107cfu.g-1, and apple orchard’s was the highest whereaswere 4.78～33.42mg.kg-1, 0.97～10.54mg.kg-1 and 0.19～0.58mg.kg-1 respectively. Total quantity of community of four fruit trees was 0.45×107～1.23×107cfu.g-1, and apple orchard’s was the highest whereas the pear’s was the lowest. The quantity of bacteria was absolutely superiority, actinomyces’ followed, fungi’ was the least. Soil nutrient index (Pi) of apple, grape, peach and pear were 0.71, 0.58, 0.54 and 0.31 respectively. The order of Pi in the same fruit trees was H＞M＞L. Synthetically analyzed, the results were that soil nutrient level and microorganism population of orchards were high pH, low SOM andtotal N, high ratio of P/K, lack of available B, less quantity of soil microorganisms in Beijing region. The basic theory of soil improvement was provided for Beijing orchards．