The invention relates to
nitrogen element
fertilizer, in particular to a
nitrogen element
fertilizer composite synergist and a preparation method thereof. The composite synergist consists of a biochemical inhibitor, a synergist, a
nitrogen element stabilizer, a carrier and microelements, the weight portion ratio of the materials is 1:0.01-1: 0.01-0.5: 0.5-1: 0-0.05, wherein the biochemical inhibitor can be a
nitrification inhibitor and a
urease inhibitor, the synergist can be poly-
aspartic acid, and the nitrogen element stabilizer can be hydrolyzed
amino acid,
humic acid,
alginic acid or
alginic acid water soluble salt. The preparation method comprises the following steps: crushing the raw materials, screening the raw materials with a
sieve of 30 to 100 meshes, and stirring and mixing the raw materials according to the proportion. The nitrogen element
fertilizer composite synergist is suitable for growing
long acting nitrogenous fertilizer taking
urea or
ammonium nitrogen fertilizer as raw materials and can be applied to various soils together with
urea or
ammonium nitrogen fertilizer so as to effectively prolong the fertilizer efficiency period of the
urea or the
ammonium nitrogen fertilizer. The fertilizer efficiency period can reach 100 to 120 days. The nitrogen element fertilizer composite synergist has remarkable resistance to diseases, drought and lodging, effectively improves the capability of soil to reserve nutrients, and has good effects for off-season crops.