The invention relates to the technical field of the water-retention
fertilizer-conservation cultivation for the drought-resistant forestation of the
agriculture and
forestry, and concretely relates to a
bentonite and fungal dreg compounded water-retention
fertilizer-conservation cultivation matrix and its preparation method. The matrix comprises 30-40 parts of
bentonite, 60-70 parts of fungal dreg and 0.1-0.5 parts of a composite
fertilizer. The preparation method of the matrix comprises the following steps: selecting new waste fungal bags after the
edible fungus plantation, carrying out bag removal treatment, crushing, and adding a composite
microbial agent and
urea to guarantee the C:N ratio of 20; fully and uniformly mixing the above raw materials, adjusting the
water content to 60%, composting the fungal dreg, and storing the obtained
compost in a ventilation and rain exposing prevention device for the decrease of the
water content to 20%; and uniformly mixing the fungal dreg with
bentonite and the composite fertilizer, and crushing to prepare the water-retention fertilizer-conservation cultivation matrix. The matrix has the advantages of abundant sources and low costs of raw materials, wide distribution and low cost of a bentonite mineral resource, large output and easy obtaining of the waste fungal dreg, simple making method, and no
pollution to the environment.