NOVELTY - Paenibacillus mucilaginosus KN-18 strain is preserved in China center for type culture collection under accession number (CCTCC NO: M2014321), and is new.    USE - Paenibacillus mucilaginosus KN-18 strain used in microbial fertilizer for cultivating rice and melon plants (claimed).    ADVANTAGE - The Paenibacillus mucilaginosus KN-18 strain utilizes microbial fertilizer that effectively increase growth in rice crops height by more than 5% and rice panicles by more than 4%, and complete growth in full rice crops by more than 7%. The yield of rice crops, is increased by more than 9%. The microbial fertilizer also increases growth in melon plants by more than 0.1. The yield of melon plants, is increased by more than 9%.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for culturing Paenibacillus mucilaginosus KN-18 strain, which involves:    (A) inoculating Paenibacillus mucilaginosus KN-18 strain onto slant culture medium, and then performing incubation at 28 degrees C for 24 hours to obtain activated Paenibacillus mucilaginosus KN-18 strain, where the slant culture medium comprises 5-15 wt.% sucrose, 0.03-2 wt.% dipotassium hydrogen phosphate, 0.2-1.5 wt.% silica, 0.01-1 wt.% magnesium sulfate, 0.05-05 wt.% calcium carbonate, 0.1-0.2 wt.% yeast extract, and 1.5-2 wt.% agar;    (B) subjecting certain amount of activated Paenibacillus mucilaginosus KN-18 strain cells into sterilized 50ml seed liquid medium, and then performing incubation on a rotary shaker (180 revolutions per minute) at 32 degrees C for 16-20 hours in 500ml Erlenmeyer flask to obtain Paenibacillus mucilaginosus KN-18 strain culture cells, where the seed liquid medium comprises 1.5-5 wt.% starch, 0.5 wt.% yeast extract, 0.5-1 wt.% sucrose, 0.1-0.5 wt.% dipotassium hydrogen phosphate, 0.1-0.5 wt.% calcium carbonate, and 0.1-0.5 wt.% silica; and    (C) subjecting certain amount of Paenibacillus mucilaginosus KN-18 strain culture cells into fermentation culture medium, and then performing fermentation on a rotary shaker (180 revolutions per minute) at 32 degrees C for 40-48 hours to obtain grown Paenibacillus mucilaginosus KN-18 strain culture cells, where the fermentation culture medium comprises 0.5-2 wt.% starch, 0.5-1 wt.% yeast extract, 1-2 wt.% sucrose, 0.5-1 wt.% yeast extract, 0.2-0.05 wt.% dipotassium hydrogen phosphate, 0.1-0.2 wt.% magnesium sulfate, and 0.05-0.1 wt.% calcium carbonate.