NOVELTY - Base fertilizer and its preparation, are claimed. The base fertilizer comprises 27-29 wt.% dried pig manure and dairy manure, 15-17 wt.% mixture of rapeseed and Ginkgo leaf, 5 wt.% castor seed cake, 6 wt.% barley, 12 wt.% river mud, 5 wt.% monosodium glutamate, 1 wt.% organic fertilizer fermentation agent, 1 wt.% organic fertilizer synergistic agent, 2 wt.% ammonium sulfate, 6 wt.% calcium superphosphate, 10 wt.% potassium chloride, 6.5 wt.% magnesium sulfate, 0.4 wt.% borax, 1 wt.% ferrous sulfate, 0.2 wt.% zinc sulfate, 0.5 wt.% ammonium citrate, and 0.3 wt.% humic acid.    USE - The base fertilizer is useful for promoting growth of Ginkgo trees.    ADVANTAGE - The fertilizer slowly releases active component for long period of 6 months, has good physical property, absorbs less moisture, is economical, less labor intensive, and rich in organic matter, nitrogen, phosphorus, potassium and microelement, does not forms block easily, and satisfies nutrient requirement in fruiting period.    DETAILED DESCRIPTION - Base fertilizer and its preparation, are claimed. The base fertilizer comprises 27-29 wt.% dried pig and dairy manure, 15-17 wt.% mixture of e.g. rapeseed and Ginkgo leaf, 5 wt.% castor seed cake, 6 wt.% barley, 12 wt.% river mud, 5 wt.% monosodium glutamate, 1 wt.% organic fertilizer fermentation agent, 1 wt.% organic fertilizer synergistic agent, 2 wt.% ammonium sulfate, 6 wt.% calcium superphosphate, 10 wt.% potassium chloride, 6.5 wt.% magnesium sulfate, 0.4 wt.% borax, 1 wt.% ferrous sulfate, 0.2 wt.% zinc sulfate, 0.5 wt.% ammonium citrate, and 0.3 wt.% humic acid. The method involves (a) crushing dried pig and dairy manure, 15-17 wt.% mixture of rapeseed and Ginkgo leaf, castor seed cake, barley, river mud in crusher, mixing the organic fertilizer fermenting agent with crushed product, adding water to mixture, and performing fermentation in autumn for 45-50 days to obtain organic fertilizer, (b) mixing organic fertilizer synergistic agent, urea, calcium superphosphate, potassium chloride, magnesium sulfate, zinc sulfate, borax, humic acid and ammonium citrate into a crusher to obtain powder-shaped organic fertilizer, and (c) mixing oraganic fertilizer of step (a) and powder-shaped organic fertilizer of step (b) to obtain product.